C2 Bonding Strucure and Name: Properties of...

C2 Bonding Strucure andProperties of Matter35 Questions

Name: ________________________

Class: ________________________

Date: ________________________

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Page 1 of 113Brookvale Groby Learning Trust

John Newlands arranged the known elements into a table in order of atomic weight.

Figure 1 shows part of Newlands’ table.

Figure 1

Group 1 2 3 4 5 6 7

H Li Be B C N O

F Na Mg Al Si P S

Cl K Ca

(a) What are the names of the elements in Group 5 of Newlands’ table?

Tick one box.

Calcium and sulfur

Carbon and silicon

Chlorine and silver

Chromium and tin

(1)

1

(b) In what order is the modern periodic table arranged?

Tick one box.

Atomic mass

Atomic number

Atomic size

Atomic weight

(1)


(c) Give two differences between Group 1 of Newlands’ table and Group 1 of the periodictable.

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(2)


(d) In 1864, atoms were thought to be particles that could not be divided up into smallerparticles.

By 1898, the electron had been discovered and the plum pudding model of an atom wasproposed.

Figure 2 shows the plum pudding model of an atom of carbon and the nuclear model of anatom of carbon.

Figure 2

Compare the position of the subatomic particles in the plum pudding model with the nuclearmodel.

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(4)


(e) Models are used to show the differences between elements, compounds and mixtures.

Which circle shows a model of a mixture?

Tick one box.

(1)

(f) Figure 3 shows a model of carbon dioxide.

Figure 3

What does each line between the atoms in Figure 3 represent?

Tick one box.

Covalent bond

Intermolecular force

Ionic bond

Metallic bond

(1)

(Total 10 marks)


The three states of matter are solid, liquid and gas.

(a) Lithium reacts with water to produce lithium hydroxide solution and hydrogen.

Use the correct state symbols from the box to complete the chemical equation.

aq g l s

2Li(s) + 2H2O(l) 2LiOH(____) + H2(____)

lithium + water lithium hydroxide + hydrogen

(2)

2


(b) Figure 1 shows the melting points and the boiling points of four substances, A, B, C and D.

Figure 1

Which substance is liquid over the greatest temperature range?

Tick one box.

A

B

C

D

(1)


(c) Which two substances are gases at 50 °C?

Tick one box.

A and B

B and C

C and D

A and D

(1)

(d) A different substance, E, has:• a melting point of −50 °C• a boiling point of +120 °C

Plot these two values on Figure 1.

(2)


(e) Figure 2 shows the apparatus a student used to determine the melting point and theboiling point of substance B in Figure 1.

Figure 2

Explain why the student could not use this apparatus to determine the boiling point ofsubstance B.

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(2)

(f) Suggest one reason why the student could not use this apparatus to determine the exactmelting point of substance B.

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(1)

(Total 9 marks)


This question is about calcium.

(a) What type of compound is calcium oxide?

Tick one box.

An acid

A base

A carbonate

A salt

(1)

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(b) Ionic compounds, such as calcium oxide, have high melting points.

Complete the sentences. Use words from the box.

bonds forces ions layers

Calcium oxide has a giant ionic lattice in which there are strong electrostatic

______________________ of attraction in all directions.

(1)


(c) The figure below shows the electronic structure of an oxygen atom and a calcium atom.

Describe how the calcium atom and the oxygen atom forms calcium oxide.

You should give the charge on each ion formed.

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(4)

(Total 6 marks)


Figure 1 shows a reactor used to produce titanium from titanium(IV) chloride.

Figure 1

The chemical equation for the reaction of titanium(IV) chloride with sodium is:

TiCl4 + 4Na Ti + 4NaCl

titanium(IV) chloride + sodium titanium + sodium chloride

(a) For one reaction:

• 1615 kg titanium(IV) chloride reacted completely with 782 kg sodium• 1989 kg sodium chloride was produced.

Calculate the mass of titanium produced from this reaction.

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Mass of titanium = _________________ kg

(1)

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(b) The table below shows the solubility of sodium chloride in 100 cm3 of aqueous solution atdifferent temperatures.

Solubility of sodium chloride in g per100cm3

Temperature in °C

35.72 10

35.89 20

36.09 30

37.37 40

36.69 50

37.04 60

On Figure 2:

• plot this data on the grid• draw a line of best fit.

Figure 2

(3)


(c) The product sodium chloride is dissolved in water to separate it from titanium.

At 30 °C the solubility of sodium chloride is 36 kg per 100 dm3.

Calculate the minimum volume of water in dm3, at 30 °C, needed to dissolve 1989 kgsodium chloride.

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Volume of water = ____________________ dm3

(2)

(d) Calculate the percentage by mass of titanium in titanium(IV) chloride (TiCl4).

Give your answer to 3 significant figures.

Relative atomic masses (Ar): Cl = 35.5; Ti = 48

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Percentage of titanium by mass = _______________ %

(3)

(e) Suggest why the reaction is done in an atmosphere of dry argon instead of air containingwater vapour.

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(3)


(f) Explain why titanium conducts electricity.

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(3)

(Total 15 marks)

Hydrogen chloride (HCl) is a gas.

(a) Complete the diagram to show all of the arrangement of the outer shell electrons of thehydrogen and chlorine atoms in hydrogen chloride.

(1)

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(b) Hydrochloric acid is a strong acid.Ethanoic acid is a weak acid.

Describe a reaction that could be used to show the difference between a weak acid and astrong acid.

You should explain why the weak acid and the strong acid give different results.

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(6)

(Total 7 marks)


The apparatus in the figure below is used to separate a mixture of liquids in a fuel.

(a) What is apparatus W on above the figure above?

Tick one box.

Beaker

Boiling Tube

Flask

Jug

(1)

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(b) What is the name of this method of separation?

Tick one box.

Crystallisation

Electrolysis

Filtration

Distillation

(1)

(c) Name the changes of state taking place at A and B in the figure above.

Use words from the box.

boiling condensing freezing melting

Change of state at A: _________________________________________________

Change of state at B: _________________________________________________

(2)


(d) Table 1 shows the boiling points of the hydrocarbons in the fuel.

Table 1

HydrocarbonBoiling point

in °C

Pentane 36

Hexane 69

Heptane 98

Octane 125

Which hydrocarbon will be the last to collect in the beaker?

Tick one box.

Pentane

Hexane

Heptane

Octane

(1)


(e) The fuel is a mixture of liquids that has been designed as a useful product.

What name is given to this type of mixture?

Tick one box.

Catalyst

Formulation

Polymer

Solvent

(1)

(f) Describe how this fuel is different from crude oil.

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(2)


(g) A student measured the melting point of a solid hydrocarbon four times.

The student’s results are in Table 2.

Table 2

Trial 1 Trial 2 Trial 3 Trial 4

Melting pointin °C

35 48 37 37

Calculate the mean melting point of the hydrocarbon, leaving out any anomalous result.

Give your answer to two significant figures.

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Mean melting point = __________________ °C

(2)

(Total 10 marks)

Aqamed is a medicine for children.

(a) The medicine is a formulation.

What is meant by a formulation?

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(1)

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(b) Children often do not like taking medicine.

Suggest a substance that could be added to Aqamed to increase the desire for children totake it.

Give a reason for your suggestion.

Substance _________________________________________________________

Reason ____________________________________________________________

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(2)


(c) The main ingredient in Aqamed is a painkiller called paracetamol.

The figure below represents a molecule of paracetamol.

Give the molecular formula of paracetamol.

Calculate its relative formula mass (Mr).

Relative atomic masses (Ar): H = 1; C = 12; N = 14; O = 16

Molecular formula ____________________________________________________

Relative formula mass ________________________________________________

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Mr = _____________________________

(2)

(d) Aspirin is a medicine for use by adults.

An aspirin tablet contains 300 mg of acetylsalicylic acid.

Calculate the number of moles of acetylsalicylic acid in one aspirin tablet.

Give your answer in standard form to three significant figures.

Relative formula mass (Mr) of aspirin = 180

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Number of moles = ______________________

(4)

(Total 9 marks)


Sulfur dioxide (SO2) is used to manufacture sulfuric acid.

(a) Explain why sulfur dioxide has a low boiling point.

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(3)

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(b) The equation shows one stage in the manufacture of sulfuric acid from sulfur dioxide.

2SO2(g) + O2(g) 2SO3 (g)

The reaction is exothermic in the forward direction.

Use Le Chatelier’s Principle to predict the effect of increasing the temperature on theamount of sulfur trioxide (SO3) produced at equilibrium.

Give a reason for your answer.

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(2)

(c) Use Le Chatelier’s Principle to predict the effect of increasing the pressure on the amountof sulfur trioxide (SO3) produced at equilibrium.

Give a reason for your answer.

(2)

(Total 7 marks)


There are several different forms of carbon and many different carbon compounds.

(a) Figure 1 shows a 3D model of a molecule of methane (CH4).

Figure 1

Draw the 2D structure of a methane molecule.

(1)

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(b) Different forms of carbon have different bonding and structure.

Draw one line from the form of carbon to the bonding and structure.

Form of carbon Bonding and structure

(3)


(c) Crude oil is a mixture of many different carbon compounds.

Crude oil can be separated into useful fractions by fractional distillation.

Figure 2 shows a column used to separate crude oil.

Figure 2

Complete the sentences.

Use words from the box.

condense evaporate freeze

Crude oil is heated so that most of the compounds ____________________

At different temperatures the compounds cool and ____________________

(2)


(d) Which fraction is the most viscous?

Tick one box.

Engine oil

Diesel oil

Kerosene

Petrol

(1)

(e) Which fraction is the most flammable?

Tick one box.

Diesel oil

Kerosene

Petrol

Refinery gas

(1)

(f) Why does kerosene separate out of the mixture before diesel oil?

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(1)

(Total 9 marks)


Carbon nanotubes are cylindrical fullerenes.

Explain the properties of carbon nanotubes.

Answer in terms of structure and bonding.

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(Total 6 marks)

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Hydrocarbons are used to make useful products.

(a) What are the elements in hydrocarbons?

Tick one box.

Carbon and hydrogen only

Carbon, hydrogen and oxygen

Carbon and nitrogen only

Carbon, nitrogen and oxygen

(1)

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(b) Table 1 gives some information about four hydrocarbons.

Table 1

Hydrocarbon Melting point in °C Boiling point in °C

Methane –183 –162

Ethene –169 –104

Octane –57 +126

Decane –30 +174

What are two correct statements about the four compounds?

Tick two boxes.

Methane has the lowest boiling point and decane has thehighest melting point

Methane and decane are both gases at 20 °C

Ethene and octane are both alkanes

Decane and ethene are both liquids at 0 °C

Octane is liquid over a larger temperature range thanmethane

(2)

(c) Ethene can be produced from long-chain hydrocarbons by cracking.

Give the conditions needed for cracking.

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(2)


(d) Poly(ethene) is a polymer made from ethene. Poly(ethene) is used to make plastic bags.

Table 2 is from a life cycle assessment comparing paper bags and plastic bags.

Table 2

Paper bag Plastic bag

Raw material Wood(renewable)

Oil or gas(non-renewable)

Energy used to make in MJ 1.7 1.5

Solid waste produced in g 50 14

Carbon dioxide produced in kg 0.23 0.53

Evaluate which type of bag is more environmentally friendly.

Use data from Table 2 and your own knowledge to support your answer.

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(6)

(Total 11 marks)


The elements in Group 1 of the periodic table are metals.

(a) The elements in Group 1 are called the alkali metals.

Why are they called the alkali metals?

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(b) Explain the increase in reactivity of elements further down the group.

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(4)

(c) Lithium oxide is an ionic compound.

Draw a dot and cross diagram to show how lithium and oxygen combine to form lithiumoxide.

Only show the electrons in the outer shell of each atom.

Give the charges on the ions formed.

(4)

(Total 10 marks)


The structures of four substances, A, B, C and D, are represented in Figure 1.

(a) Use the correct letter, A, B, C or D, to answer each question.

(i) Which substance is a gas?

(1)

(ii) Which substance is a liquid?

(1)

(iii) Which substance is an element?

(1)

(iv) Which substance is made of ions?

(1)

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(b) Figure 2 shows the bonding in substance C.

(i) What is the formula of substance C?

Draw a ring around the correct answer.

SO2 SO2 S2O

(1)

(ii) Use the correct answer from the box to complete the sentence.

delocalised shared transferred

When a sulfur atom and an oxygen atom bond to produce substance C,

electrons are _____________________________________________

(1)

(iii) What is the type of bonding in substance C?

Draw a ring around the correct answer.

covalent ionic metallic

(1)

(Total 7 marks)


This question is about magnesium.

(a) (i) The electronic structure of a magnesium atom is shown below.

Use the correct answer from the box to complete each sentence.

electrons neutrons protons shells

The nucleus contains protons and _________

The particles with the smallest relative mass that move around the nucleus are called

_________

Atoms of magnesium are neutral because they contain the same number of

electrons and _________

(3)

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(ii) A magnesium atom reacts to produce a magnesium ion.

Which diagram shows a magnesium ion?

Tick ( ) one box.

(1)


(b) Magnesium and dilute hydrochloric acid react to produce magnesium chloride solution andhydrogen.

Mg(s) + 2 HCl(aq) MgCl2(aq) + H2(g)

(i) State two observations that could be made during the reaction.

1. ____________________________________________________________

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2. ____________________________________________________________

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(2)

(ii) In this question you will be assessed on using good English, organisinginformation clearly and using specialist terms where appropriate.

Describe a method for making pure crystals of magnesium chloride from magnesiumand dilute hydrochloric acid.

In your method you should name the apparatus you will use.

You do not need to mention safety.

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(6)

(Total 12 marks)


This question is about copper.

(a) Copper can be extracted by smelting copper-rich ores in a furnace.

The equation for one of the reactions in the smelting process is:

Cu2S(s) + O2(g) 2 Cu(s) + SO2(g)

Explain why there would be an environmental problem if sulfur dioxide gas escaped intothe atmosphere.

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(b) The impure copper produced by smelting is purified by electrolysis, as shown below.

Copper atoms are oxidised at the positive electrode to Cu2+ ions, as shown in the halfequation.

Cu(s) Cu2+(aq) + 2e−

(i) How does the half equation show that copper atoms are oxidised?

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(1)


(ii) The Cu2+ ions are attracted to the negative electrode, where they are reduced toproduce copper atoms.

Write a balanced half equation for the reaction at the negative electrode.

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(1)

(iii) Suggest a suitable electrolyte for the electrolysis.

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(1)

(c) Copper metal is used in electrical appliances.

Describe the bonding in a metal, and explain why metals conduct electricity.

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(4)

(d) Soil near copper mines is often contaminated with low percentages of copper compounds.

Phytomining is a new way to extract copper compounds from soil.

Describe how copper compounds are extracted by phytomining.

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(3)


(e) A compound in a copper ore has the following percentage composition by mass:

55.6% copper, 16.4% iron, 28.0% sulfur.

Calculate the empirical formula of the compound.

Relative atomic masses (Ar): S = 32; Fe = 56; Cu = 63.5

You must show all of your working.

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Empirical formula = ______________________________

(4)

(Total 16 marks)

Methane (CH4) is used as a fuel.

(a) The displayed structure of methane is:

Draw a ring around a part of the displayed structure that represents a covalent bond.

(1)

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(b) Why is methane a compound?

Tick ( ) one box.

Methane contains atoms of two elements, combined chemically.

Methane is not in the periodic table.

Methane is a mixture of two different elements.

(1)

(c) Methane burns in oxygen.

(i) The diagram below shows the energy level diagram for the complete combustion ofmethane.

Draw and label arrows on the diagram to show:

• the activation energy• the enthalpy change, ΔH.

(2)

(ii) Complete and balance the symbol equation for the complete combustion of methane.

CH4 + _____ CO2 + _____

(2)


(iii) Explain why the incomplete combustion of methane is dangerous.

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(2)

(iv) Explain why, in terms of the energy involved in bond breaking and bond making, thecombustion of methane is exothermic.

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(3)


(d) Methane reacts with chlorine in the presence of sunlight.

The equation for this reaction is:

Some bond dissociation energies are given in the table.

BondBond dissociation

energyin kJ per mole

C−H 413

C−Cl 327

Cl−Cl 243

H−Cl 432

(i) Show that the enthalpy change, ΔH, for this reaction is −103 kJ per mole.

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(3)


(ii) Methane also reacts with bromine in the presence of sunlight.

This reaction is less exothermic than the reaction between methane and chlorine.

The enthalpy change, ΔH, is −45 kJ per mole.

What is a possible reason for this?

Tick ( ) one box.

CH3Br has a lower boiling point than CH3Cl

The C−Br bond is weaker than the C−Cl bond.

The H−Cl bond is weaker than the H−Br bond.

Chlorine is more reactive than bromine.

(1)

(Total 15 marks)

This question is about electrolysis.

(a) Metal spoons can be coated with silver.This is called electroplating.

Suggest one reason why spoons are electroplated.

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(1)

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(b) When sodium chloride solution is electrolysed the products are hydrogen and chlorine.

(i) What is made from chlorine?

Tick ( ) one box.

Bleach

Fertiliser

Soap

(1)

(ii) Sodium chloride solution contains two types of positive ions, hydrogen ions (H+) andsodium ions (Na+).

Why is hydrogen produced at the negative electrode and not sodium?

Tick ( ) one box.

Hydrogen is a gas.

Hydrogen is less reactive than sodium.

Hydrogen ions move faster than sodiumions.

(1)


(iii) Hydrogen and chlorine can be used to produce hydrogen chloride.

The diagrams in Figure 1 show how the outer electrons are arranged in an atom ofhydrogen and an atom of chlorine.

Complete Figure 2 to show how the outer electrons are arranged in a molecule ofhydrogen chloride (HCl).

(1)

(iv) What is the type of bond in a molecule of hydrogen chloride?

Tick ( ) one box.

Covalent

Ionic

Metallic

(1)


(v) Why is hydrogen chloride a gas at room temperature (20 °C)?

Tick ( ) two boxes.

Hydrogen chloride has a low boiling point.

Hydrogen chloride has a high melting point.

Hydrogen chloride is made of simple molecules.

Hydrogen chloride does not conduct electricity.

Hydrogen chloride has a giant structure.

(2)

(c) Aluminium is produced by electrolysis of a molten mixture of aluminium oxide and cryolite.This is shown in Figure 3.

(i) Name a gas produced at the positive electrode.

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(1)


(ii) Aluminium ions move to the negative electrode.

Explain why.

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(2)

(iii) At the negative electrode, the aluminium ions gain electrons to produce aluminium.

What is this type of reaction called?

Tick ( ) one box.

Combustion

Oxidation

Reduction

(1)

(iv) Aluminium has layers of atoms, as shown in Figure 4.

Complete the sentence.

Metals can be bent and shaped because the layers of atoms can ___

(1)


(d) Electrodes used in the production of aluminium are made from graphite.

(i) Which diagram, A, B or C, shows the structure of graphite?

The structure of graphite is shown in diagram

(1)

(ii) The temperature for the electrolysis is 950 °C.

Use the correct answer from the box to complete the sentence.

cross links a giant ionic lattice strong covalent bonds

The graphite does not melt at 950 °C because

graphite has _____________________________ .

(1)

(Total 14 marks)

This question is about compounds.

(a) The table gives information about the solubility of some compounds.

Soluble compounds

All potassium and sodium salts

All nitrates

Chlorides, bromides and iodides, except those of silver and lead

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Use information from the table to answer these questions.

(i) Name a soluble compound that contains silver ions.

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(1)

(ii) Name a soluble compound that contains carbonate ions.

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(1)

(b) Metal oxides react with acids to make salts.

What type of compound is a metal oxide?

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(1)

(c) Lead nitrate solution is produced by reacting lead oxide with nitric acid.

(i) State how solid lead nitrate can be obtained from lead nitrate solution.

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(1)

(ii) Balance the equation for the reaction.

PbO + HNO3 Pb(NO3)2 + H2O

(1)

(iii) Give the total number of atoms in the formula Pb(NO3)2

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(1)


(d) An oxide of lead that does not have the formula PbO contains 6.21 g of lead and 0.72 g ofoxygen.

Calculate the empirical formula of this lead oxide.

Relative atomic masses (Ar): O = 16; Pb = 207

You must show your working to gain full marks.

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Empirical formula = ____________________

(4)

(Total 10 marks)

This question is about sodium chloride and iodine.

(a) Describe the structure and bonding in sodium chloride.

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(b) When sodium chloride solution is electrolysed, one product is chlorine.

Name the two other products from the electrolysis of sodium chloride solution.

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(2)


(c) Many people do not have enough iodine in their diet.

Sodium chloride is added to many types of food. Some scientists recommend that sodiumchloride should have a compound of iodine added.

Give one ethical reason why a compound of iodine should not be added to sodium chlorideused in food.

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(1)

(d) The bonding in iodine is similar to the bonding in chlorine.

(i) Complete the diagram below to show the bonding in iodine.

Show the outer electrons only.

(2)

(ii) Explain why iodine has a low melting point.

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(3)

(iii) Explain, in terms of particles, why liquid iodine does not conduct electricity.

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(2)

(Total 14 marks)


Iron is extracted from iron oxide in the blast furnace.

(a) The equation for one of the reactions in the blast furnace is:

Fe2O3 + 3CO 2Fe + 3CO2

(i) Complete the word equation for this reaction.

iron oxide+

carbonmonoxide ________________ + ________________

(2)

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(ii) Oxygen is removed from iron oxide in the blast furnace.

Draw a ring around the correct answer to complete the sentence.

The iron oxide is

neutralised.

oxidised.

reduced.

(1)


(b) The diagrams represent pure iron and iron from the blast furnace.

Pure iron Iron from the blast furnace

(i) Draw one line from each statement to the correct explanation.

(2)

(ii) Explain why iron from the blast furnace is harder than pure iron.

Use the diagrams on page 4 to help you.

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(2)

(Total 7 marks)


(a) The diagram shows an atom of magnesium and an atom of chlorine.

21

Magnesium Chlorine

Describe, in terms of electrons, how magnesium atoms and chlorine atoms change intoions to produce magnesium chloride (MgCl2).

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(4)

(b) Calculate the relative formula mass (Mr) of magnesium chloride (MgCl2).

Relative atomic masses (Ar): magnesium = 24; chlorine = 35.5

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Relative formula mass (Mr) = ________

(2)

(Total 6 marks)


(a) A particle of ammonia is represented by the formula NH3 or as:

(i) How many different elements are there in a particle of ammonia?

_______________________________

(1)

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(ii) Draw a ring around the correct answer to complete the sentence.

A particle of ammonia is called

an atom.

an ion.

a molecule.

(1)

(iii) Complete the dot and cross bonding diagram for ammonia.

Show only electrons in the outer energy level of each atom.

(2)

(b) Ammonia gas reacts with hydrogen chloride gas to produce a white solid.

The formula of the white solid is NH4Cl

(i) Complete the equation by adding the correct state symbols.

NH3(g) + HCl(____) NH4Cl(____)

(1)

(ii) The white solid has the formula NH4Cl

Complete the name of the white solid.

Ammonium _______________________________

(1)


(c) Concentrated ammonia solution gives off ammonia gas.

Concentrated hydrochloric acid gives off hydrogen chloride gas.

Apparatus was set up as shown in Diagram 1.

Diagram 1 Cotton wool soaked

in concentratedhydrochloric acid

Cotton wool soakedin concentratedammonia solution

(i) Concentrated hydrochloric acid is corrosive.

Give one safety precaution you should take when using concentrated hydrochloricacid.

______________________________________________________________

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(1)

(ii) After 3 minutes a white solid was seen in the glass tube, as shown in Diagram 2.

Diagram 2 Cotton wool soaked

in concentratedhydrochloric acid

Cotton wool soakedin concentratedammonia solution

White solid formed here

Suggest why the white solid is seen nearer the concentrated hydrochloric acid thanthe concentrated ammonia.

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(1)


(iii) The experiment was repeated at a higher temperature.

Explain why the white solid was produced in less than 3 minutes.

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(2)

(Total 10 marks)

Sulfur is a non-metal.

Sulfur burns in the air to produce sulfur dioxide, SO2

(a) Why is it important that sulfur dioxide is not released into the atmosphere?

Tick (✔) one box.

Sulfur dioxide causes acid rain.

Sulfur dioxide causes global dimming.

Sulfur dioxide causes global warming.

(1)

23

(b) Sulfur dioxide dissolves in water.

What colour is universal indicator in a solution of sulfur dioxide?Give a reason for your answer.

___________________________________________________________________

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(2)


(c) Sulfur dioxide is a gas at room temperature.

The bonding in sulfur dioxide is covalent.

Explain, in terms of its structure and bonding, why sulfur dioxide has a low boiling point.

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(3)

(d) In this question you will be assessed on using good English, organising information clearlyand using specialist terms where appropriate.

Sulfur dioxide is produced when fossil fuels are burned.

It is important that sulfur dioxide is not released into the atmosphere.

Three of the methods used to remove sulfur dioxide from gases produced when fossil fuelsare burned are:

• wet gas desulfurisation ( W)

• dry gas desulfurisation ( D)

• seawater gas desulfurisation ( S).

Information about the three methods is given in the bar chart and in Table 1 and Table 2.

Method of removing sulfur dioxide


Table 1

Method Material used How material is obtained

W Calcium carbonate, CaCO3 Quarrying

DCalcium oxide, CaO Thermal decomposition of calcium

carbonate:

CaCO3 CaO + CO2

S Seawater From the sea

Table 2

Method What is done with waste material

WSolid waste is sold for use in buildings.Carbon dioxide is released into the atmosphere.

D Solid waste is sent to landfill.

S Liquid waste is returned to the sea.


Evaluate the three methods of removing sulfur dioxide from waste gases.

Compare the three methods and give a justified conclusion.

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(6)

(Total 12 marks)

Diagram 1 shows the apparatus used to electrolyse magnesium sulfate solution.

Diagram 1

Gases were given off at both electrodes.

24


(a) The gas collected at the anode was oxygen.

Draw one line from the test for oxygen to the correct result.

(1)

(b) (i) The gas collected at the cathode was hydrogen.

Describe how to test the gas to show that it is hydrogen.

Test __________________________________________________________

______________________________________________________________

Result ________________________________________________________

______________________________________________________________

(2)

(ii) Why is hydrogen, and not magnesium, produced at the cathode?

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(1)

(c) A student wanted to use electrolysis to silver plate a metal spoon.

(i) Give one reason why metal spoons are sometimes silver plated.

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(1)


(ii) Diagram 2 shows the apparatus the student used. The student did not set theapparatus up correctly.

Diagram 2

d.c. powersupply

The student found that the metal spoon eroded and a thin layer of copper formed onthe pure silver electrode.

Suggest two changes that the student must make to his apparatus to be able to silverplate the metal spoon. Give a reason for each change.

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(4)

(iii) Why is it difficult to electroplate plastic spoons?

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(1)

(Total 10 marks)


A student investigated the conductivity of different concentrations of sodium chloride solution.The student set the apparatus up as shown in Figure 1.

Figure 1

25

The student measured the conductivity of the pure water with a conductivity meter.

The reading on the conductivity meter was zero.

(a) The student:

• added sodium chloride solution one drop at a time• stirred the solution• recorded the reading on the conductivity meter.

The student’s results are shown in the table below.


Number of drops ofsodium chloride solution

added

Relative conductivityof solution

0 0

1 100

2 120

3 310

4 400

5 510

6 590

7 710

8 800


(i) The student plotted the results on the grid shown in Figure 2.

Plot the four remaining results.

Draw a line of best fit, ignoring the anomalous result.

Figure 2

Number of drops of sodium chloride added

(3)

(ii) One of the points is anomalous.

Suggest one error that the student may have made to cause the anomalous result.

______________________________________________________________

______________________________________________________________

(1)


(iii) The student wanted to compare the conductivity of sodium chloride solution with theconductivity of potassium chloride solution.

State one variable he should keep constant when measuring the conductivity of thetwo solutions.

______________________________________________________________

(1)

(b) (i) Explain, in terms of bonding, why pure water does not conduct electricity.

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(2)

(ii) Explain why sodium chloride solution conducts electricity.

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(2)

(iii) After he had added sodium chloride solution, the student noticed bubbles of gas atthe negative electrode.

Complete the sentence.

The gas produced at the negative electrode is __________________

(1)

(Total 10 marks)


In this question you will be assessed on using good English, organising informationclearly and using specialist terms where appropriate.

Explain why chlorine (Cl2) is a gas at room temperature, but sodium chloride (NaCl) is a solid atroom temperature.

Chlorine Sodium chloride

Include a description of the bonding and structure of chlorine and sodium chloride in youranswer.

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Extra space _____________________________________________________________

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(Total 6 marks)

26


Carbon atoms are used to make nanotubes.

© Denis Nikolenko/Hemera/Thinkstock

Carbon atoms in a nanotube are bonded like a single layer of graphite.

The figure below shows the structure of a single layer of graphite.

© Evgeny Sergeev/iStock/Thinkstock

(a) Suggest why carbon nanotubes are used as lubricants.

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(2)

27

(b) Explain why graphite can conduct electricity.

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(2)

(Total 4 marks)


Glass is made from silicon dioxide.

© Velirina/iStock/Thinkstock

(a) Silicon dioxide has a very high melting point.

Other substances are added to silicon dioxide to make glass. Glass melts at a lowertemperature than silicon dioxide.

Suggest why.

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(1)

28

(b) Sodium oxide is one of the substances added to silicon dioxide to make glass.

(i) Sodium oxide contains Na+ ions and O2– ions.

Give the formula of sodium oxide.

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(1)

(ii) Sodium oxide is made by heating sodium metal in oxygen gas.

Complete the diagram to show the outer electrons in an oxygen molecule (O2).

(2)


(c) Glass can be coloured using tiny particles of gold. Gold is a metal.

Describe the structure of a metal.

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(3)

(Total 7 marks)

The diagram shows a small part of the structure of silicon dioxide.

(a) Use the diagram above to answer the question.

Draw a ring around the correct answer to complete each sentence.

two

In silicon dioxide, each silicon atom is bonded with three oxygen atoms.

four

ionic.

The bonds in silicon dioxide are covalent.

metallic.

(2)

29


(b)

© Oleksiy Mark/iStock

Silicon dioxide is used as the inside layer of furnaces.

Suggest why.

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(1)

(c) Nanowires can be made from silicon dioxide.

Draw a ring around the correct answer to complete the sentence.

brittle.

The word ‘nano’ means the wires are very thick.

thin.

(1)

(Total 4 marks)


Kelp is a seaweed.

Kelp can be burned to give out energy.

© Ethan Daniels/Shutterstock

(a) Draw a ring around the correct answer to complete each sentence.

endothermic.

Reactions which give out energy are exothermic.

reversible.

(1)

30

(b) Which two of the following questions cannot be answered by scientific experiments alone?

Tick ( ) two boxes.

Question Tick ( )

How much carbon dioxide is produced when 100 g of kelp is burned?

Does kelp give out more heat energy than coal when burned?

Should people use kelp instead of oil as an energy source?

Will kelp be more popular than coal in the next 10 years?

(2)


(c) Potassium iodide can be produced from kelp.

(i) Potassium can be reacted with iodine to produce potassium iodide.

potassium + iodine → potassium iodide

The diagram shows how this happens.

Only the outer electrons are shown.

The dots (●) and crosses (×) are used to represent electrons

Use the diagram to help you answer this question.

Describe, as fully as you can, what happens when potassium reacts with iodine toproduce potassium iodide.

To get full marks you should use the words atom, electron and ion in your answer.

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(4)


(ii) Potassium iodide reacts with lead nitrate.

2 KI(aq) + Pb(NO3)2(aq) → 2 KNO3(aq) + PbI2(s)

Why is this reaction a precipitation?

______________________________________________________________

______________________________________________________________

(1)

(iii) How can the precipitate be removed from the reaction mixture?

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______________________________________________________________

(1)

(Total 9 marks)

Thermosoftening polymers can be used to make plastic bottles and food packaging.

(a) Why are thermosoftening polymers not suitable for storing very hot food?

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___________________________________________________________________

(1)

31

(b) The reaction to produce the polymers uses a catalyst.

Why are catalysts used in chemical reactions?

___________________________________________________________________

___________________________________________________________________

(1)

(c) Compounds from food packaging must not get into food.

Gas chromatography can be used to separate compounds in food.

The output from the gas chromatography column can be linked to an instrument which canidentify the compounds.

(i) Name the instrument used to identify the compounds.

______________________________________________________________

______________________________________________________________

(1)


(ii) Give one reason why instrumental methods of analysis are used to identify thecompounds.

______________________________________________________________

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(1)

(d) Poly(ethene) is a thermosoftening polymer.

Poly(ethene) can be made with different properties. The properties depend on theconditions used when poly(ethene) is made.

Suggest two conditions which could be changed when poly(ethene) is made.

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(2)

(Total 6 marks)

The electrolysis of sodium chloride solution is an industrial process.

The diagram shows the apparatus used in a school experiment.

(a) One of the products of the electrolysis of sodium chloride solution is hydrogen.

(i) Why do hydrogen ions move to the negative electrode?

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______________________________________________________________

(1)

32

(ii) How does a hydrogen ion change into a hydrogen atom?

______________________________________________________________

______________________________________________________________

(1)


(b) Hydrogen is used to make ammonia (NH3).

Complete the diagram to show the bonding in ammonia.

Use dots (●) and crosses (x) to show electrons.

Show only outer shell electrons.

(2)

(c) The table shows the ions in sodium chloride solution.

Positive ions Negative ions

hydrogen chloride

sodium hydroxide

In industry, some of the waste from the electrolysis of sodium chloride solution is alkalineand has to be neutralised.

(i) Which ion makes the waste alkaline?

______________________________________________________________

(1)

(ii) This waste must be neutralised.

Write the ionic equation for the neutralisation reaction.

______________________________________________________________

(1)


(d) In this question you will be assessed on using good English, organising information clearlyand using specialist terms where appropriate.

The electrolysis of sodium chloride solution also produces chlorine and sodium hydroxide.

In industry, the electrolysis of sodium chloride solution can be done in several types ofelectrolysis cell.

Some information about two different types of electrolysis cell is given below.

Mercury cell Membrane cell

Cost of construction Expensive Relatively cheap

Additional substances used

Mercury, which is recycled.Mercury is toxic so anytraces of mercury must beremoved from the waste

Membrane, which is madeof a polymer. Themembrane must bereplaced every 3 years.

Amount of electricity usedfor each tonne of chlorineproduced in kWh

3400 2950

Quality of chlorine produced PureNeeds to be liquefied anddistilled to make it pure.

Quality of sodium hydroxidesolution produced

50% concentration. Steam isused to concentrate thesodium hydroxide solutionproduced.

30% concentration. Steamis used to concentrate thesodium hydroxide solutionproduced.


Use the information and your knowledge and understanding to compare the environmentaland economic advantages and disadvantages of these two types of electrolysis cell.

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(6)

(Total 12 marks)


Kelp is a seaweed.

Kelp can be used in foods and as a renewable energy source.

© Ethan Daniels/Shutterstock

(a) Scientific experiments, on their own, cannot fully answer one of the following questions.Which one?

Tick ( ) one box.

Questions Tick (✔✔✔✔)

How much carbon dioxide is produced when 100 g of kelp is burned?

Does kelp give out more heat energy than coal?

Will kelp last longer than coal as an energy source?

Which fuel, kelp or coal, produces the most ash when burned?

(1)

33

(b) Scientists cannot answer the question ‘should people use kelp instead of coal as an energysource?’

Give two reasons why.

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___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(2)


(c) Sodium iodide can be produced from kelp.

(1)

(i) How many electrons are in the outer shell of an iodine atom?

(ii) Sodium iodide contains sodium ions (Na+) and iodide ions (I–).

Describe, as fully as you can, what happens when sodium atoms react with iodineatoms to produce sodium iodide.

You may use a diagram in your answer

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(3)


(iii) The diagram shows the structure of sodium iodide.

Solid sodium iodide does not conduct electricity.

Why does sodium iodide solution conduct electricity?

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(1)

(iv) When sodium iodide solution is electrolysed, iodine is formed at the positiveelectrode.

Complete and balance the half equation for the formation of iodine.

_____I− → I2 + _____e−

(1)

(v) What is formed at the negative electrode when sodium iodide solution is electrolysed?

Explain why.

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(2)

(Total 11 marks)


Silicon dioxide is used as a lining for furnaces.

Furnaces can be used to melt iron for recycling.

© Oleksiy Mark/iStock

The diagram shows a small part of the structure of silicon dioxide.

Explain why silicon dioxide is a suitable material for lining furnaces.

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(Total 4 marks)

34


The picture shows a student filling in a multiple choice answer sheet using a pencil.

© Cihan Ta?k?n/iStock

The pencil contains graphite. Graphite rubs off the pencil onto the paper.

Diagrams 1 and 2 show how the atoms are arranged in graphite.

(a) Use the diagrams to help you explain why graphite can rub off the pencil onto the paper.

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________

(2)

35

(b) Draw a ring around the type of bond which holds the atoms together in each layer.

covalent ionic metallic

(1)

(Total 3 marks)


Mark schemes

(a) Carbon and silicon11

(b) Atomic number1

(c) Hydrogen / fluorine / chlorine are not in Group 1 of the periodic tableorHydrogen and fluorine / chlorine are not in the same group of the periodic table

1Lithium / sodium / potassium are in Group 1 of the periodic table

1

(d) plum pudding model has a single ball of positive charge and nuclear model has positivecharges in the centre / nucleus

1

plum pudding model has electrons in random positions and nuclear model has electronsin fixed positions

1

plum pudding model has no nucleus and the nuclear model has a nucleus1

plum pudding model has no neutrons and the nuclear model has neutrons in the nucleus1

(e)

1

(f) Covalent bond1

[10]

(a) LiOH (aq)

this order1

2

H2 (g)1

(b) C1

(c) A and D1

(d) point x at −10 °C1


point ● at +150 °C1

(e) substance B will not reach its boiling point of 190 °C1

because the boiling point of water is only 100 °C1

(f) there is too much substance B to melt instantly.

allow answers based on thermal conductivity or temperaturegradient from the wall of the test tube to the thermometer

1

[9]

(a) A base13

(b) forces1

(c) calcium loses electrons and oxygen gains electrons

max 3 for incorrect reference to atom / ion or to oxygen / oxide1

two electrons are transferred1

calcium has a 2+ charge1

oxide has a 2– charge1

[6]

(a) 408 kg14

(b) all points correct

± ½ small square2

allow 1 mark if 5 points correct

best fit line1

(c)

1

5525 dm3

1

(d) relative formula mass of TiCl4 is 1901


25.26 %1

Answer given to 3 significant figures = 25.3 %1

25.23% with or without working gains 3 marks

(e) argon is unreactive1

water (vapour) would react with sodium

allow water (vapour) would react with titanium(IV) chloride1

and air contains oxygen that would react with reactants

allow and air contains oxygen that would react with products1

(f) (titanium conducts electricity) because electrons in the outer shell of the metal atoms aredelocalised

1

and so electrons are free to move

allow the delocalised electrons in the metal carry electrical chargethrough the metal

1

through the whole structure1

[15]

(a) bonded pair of electrons and

6 non-bonded electrons on chlorine1

5


(b) Level 3 (5–6 marks):A detailed and coherent explanation of comparative results of a reaction in terms ofconcentration and ionisation. The response makes logical links between the pointsraised and uses sufficient examples to support these links.

Level 2 (3–4 marks):A description of a reaction with results is given but may miss some details. Links are madebut may not be fully articulated and / or precise.

Level 1 (1–2 marks):Simple statements are made. The response may fail to make logical links between thepoints raised.

0 marks:No relevant content

Indicative content

Simple statements / descriptions of a reaction• correct comparative pH, such as, 0–3 (strong) 4–6 (weak)• named reaction, such as, with a reactive metal or a named carbonate• comparative results or observations of the named reaction, such as, faster

reaction (strong) or greater volume of gas produced in a given time (strong)

Explanations of different results• weak acids are only partially ionised in aqueous solution• strong acids are completely ionised in aqueous solution / greater

concentration of H+ ions• aqueous solutions of acids at the same concentration / same state of division

of metal / powder, same temperature6

[7]

(a) Flask16

(b) Fractional distillation1

(c) A – boiling

in this order1

B – condensing1

(d) Pentane1

(e) Formulation1

(f) the fuel is a pure compound1


and crude oil is a mixture

or

the fuel is made up of four hydrocarbons

allow crude oil contains a large number of compounds and the fuelcontains four

and crude oil could have many more1

(g) (35 + 37 + 37 / 3) = 36.331

361

allow (35 + 48 + 37 + 37 / 4 =) 39(.25) for 1 mark

[10]

(a) (medicine is) a mixture and

(designed as) a useful product1

7

(b) sugar / flavouring1

to make it taste better

or

colouring

to make it look more attractive1

(c) C8H9NO2any order of elements

1

1511

(d) mass of acetylsalicylic acid = 0.3 g1

=

method mark – divide mass by Mr1

= 0.00167 (mol)

allow 0.0016666(66)1


1.67 × 10-3 (mol)

correct answer with or without working scores 4 marks

allow ecf from steps1, 2 and 31

[9]

(a) small molecules18

with weak intermolecular forces1

(so) only a small amount of energy is needed to separate the molecules

any reference to bonds being weak or being broken negates thesecond and third mark unless they are stated to be intermolecularbonds or bonds between molecules

1

(b) decreases1

because the equilibrium shifts in the endothermic direction

allow reverse reaction favoured if forward reaction is exothermic1

(c) increases1

because there are more molecules of gas on the left-hand side

or converse1

[7]

(a)

1

9


(b) Form of carbon Bonding and structure

extra lines from the left negate the mark3

(c) evaporate1

condense1

(d) Engine oil1

(e) Refinery gas1

(f) because its boiling point is lower1

[9]


Level 3 (5–6 marks):A detailed and coherent explanation applying knowledge of the properties of nanotubes, withclear and logical links to reasons why carbon nanotubes have these properties

Level 2 (3–4 marks):Description contains relevant statements that demonstrate clear knowledge of the properties ofnanotubes. Attempt made to link properties to explanation of why these properties occur, butlogic may be unclear

Level 1 (1–2 marks):Simple relevant statements of the properties of nanotubes, demonstrating knowledge, but nolinking to an explanation of why these properties occur.

0 marks:No relevant content.

Indicative content

properties:• high tensile strength• high electrical / thermal conductivity• high melting point

explanations:• nanotubes are fullerenes based on hexagonal rings of carbon atoms• which means that each carbon forms three covalent bonds with three other carbon

atoms• covalent bonds are strong or need a lot of energy to break them• so nanotubes are strong / have high tensile strength• and have a high melting point• the structure means that one electron from each carbon atom is delocalised• as in metals and graphite, the delocalised electrons can move throughout the

structure• allowing the carbon nanotube / fullerene to conduct thermal energy and electricity

[6]

10

(a) Carbon and hydrogen only111

(b) Methane has the lowest boiling point and decane has the highest melting point1

Octane is liquid over a larger temperature range than methane1

(c) heat / steam1

catalyst1


(d) Level 3 (5–6 marks):A detailed and coherent evaluation is provided that considers a range of relevant points,quotes relevant data from the table and comes to a conclusion consistent with thereasoning.

Level 2 (3–4 marks):An attempt to describe relevant points which comes to a conclusion. The logic and useof data may be inconsistent at times but builds towards a coherent argument.

Level 1 (1–2 marks):Discrete, relevant points made. The logic may be unclear and the conclusion, if present,may not be consistent with the reasoning.

0 marks:No relevant content.

Indicative content• conclusion as to which bag is more environmentally friendly

Points that may be used in argument• Paper bags are made from a renewable resource (wood)• Paper bags more sustainable• Paper bags are biodegradable• Plastic bags are made from a finite resource (oil or gas)• Plastic bags not sustainable• Paper bags require more energy to manufacture (1.7 MJ compared with

1.5 MJ)• Paper bags produce more waste (50 g compared with 14 g)• Paper bags create less CO 2 than plastic bags• So manufacture of plastic bags has more effect on

C2 Bonding Strucure and Name: Properties of...

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