The Chemical Earth Topic Test

the chemical earth

Topic test

FEBRUARY 27, 2015

1. The diagram below shows the relative abundances of elements in the lithosphere.

Which of the following statements is true?(A) Metals are more abundant than non-metals in the lithosphere. (B) Oxygen is commonly present as a gas in the lithosphere.(C) Silicon is the most abundant non-metal in the lithosphere. (D) Aluminium is the most abundant metal in the lithosphere.

2. Which of the following reactions is incorrect?(A) silver chloride → silver + chlorine + light(B) copper(II) carbonate + heat → copper(II) oxide + carbon dioxide(C) magnesium + oxygen + heat → magnesium oxide + light + heat(D) water + electricity → hydrogen + oxygen

3. Identify from the examples the reaction which represents a physical change.(A) Decomposition of copper carbonate (B) Condensation of water vapour (C) Electrolysis of water (D) Burning of Hydrogen

4. Given the following processes

i. production of oxygen gas when mercury (II) oxide is heated.ii. production of water vapour when water is boiled.

iii. production of misty cloud when dry ice is placed in water.iv. production of water droplets on the outside of a soft drink bottle when taken out of the

fridge.

Which of the processes is a chemical change?

(A) (i) only(B) (i) & (iii) only(C) (i), (iii) & (iv) only(D) (i), (ii), (iii) & (iv)

5. Which of the following substances has the greatest ionic bond strength?

Substance Melting Point (oC)

(A) ZnO 1970

(B) HgO d* 500

(C) MgO 2800

(D) graphite 3730

* decomposes

6. Which of the following is not a molecule?

(A) He(B) N2

(C) NH3

(D) Al

7. Of the four ions below, which of the following statements is true?

(A)The number of neutrons is the same in each.(B) They are all members of the same periodic group.(C) They all belong to the same period.(D)They all contain the same number of electrons.

8. The characteristics of a certain solid, X, is detailed in the table below along with some other known substances.

Substance Appearance Conductivity (MS m-1) at 25oC

carbon (graphite) dull black 0.07

magnesium silvery 23

phosphorus dull white 10-15

X silvery-white 10-3

What is X likely to be?

(A) metal(B) non-metal(C) semi-metal(D) noble gas

9. The physical properties of solid metals can best be explained by which of the following?

(A) Each atom is bonded in the crystal lattice by covalent bonds.(B) Positive metal ions are arranged in an orderly way, with valence electrons able to

move freely through the crystal lattice.(C) Positive and negative metal ions are arranged in an orderly way, with mobile valence

electrons able to migrate easily around the crystal lattice.(D) Each metal atom is surrounded by a variable number of valence electrons which

complete the "noble gas" electronic structure in the crystal lattice.

10. Sydney’s main water supply comes from Warragamba dam. Before being distributed to Sydney households, the water is first purified in one of the various purification plants in the outskirts of the city. What process do you think is being used to remove relatively large (pebble sized) debris from the water?

(A)sieving(B) evaporation(C) distillation(D)filtration

11. The flow chart below shows the extraction of zinc metal from the mineral sphalerite in four steps.

Which steps in this process are chemical changes and which steps are physical changes?

Chemical Changes Physical Changes

A Step 1 Steps 2, 3 and 4

B Step 1 and 3 Steps 2 and 4

C Steps 2 and 4 Steps 1 and 3

D Steps 2, 3 and 4 Step 1

12. The table below shows the melting point of four different chlorides.

Compound Formula Melting Point ( oC)

hydrogen chloride HCl -114

nitrogen trichloride NC13 -27

silicon tetrachloride SiCl4 -68

sodium chloride NaCl 801

Why does sodium chloride have a much higher melting point than the other three compounds?(A)Sodium chloride has a greater molar mass than the other three.(B) Sodium chloride is ionic while the other three are covalent molecular substances. (C) The intermolecular forces are greater in sodium chloride than in the other three.(D)The percentage of chlorine by mass is lower in the sodium chloride than in the other three.

Question 13 (5 marks)The properties of five substances are listed below

Substance MP.(°C)

B.P.(°C)

Density(g ml-1)

Solubility inwater

Solubility inoctane

silicon dioxide 1700 2230 2.6 no no

potassium iodide 681 1324 3.1 yes no

naphthalene 80 218 1.2 no yes

water 0 100 1.0 yes no

octane -95 111 1.5 no yes

Use the information in the table to answer the following questions(A) Which two substances could be separated from each other using a separating funnel? [1]

..........................................................................................................................................

..........................................................................................................................................

(B) All of these substances were placed in a large test-tube, shaken up and then allowed to settle. Assume that the density of any solution is similar to that of the solvent.Use a labelled diagram to show the composition of each layer. [2]

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

(C) Describe the steps necessary to separate the potassium iodide from the mixture in the test tube. [2]

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

Question 14 (3 marks)Explain the relationship between reactivity of an element and the likelihood of it existing on Earth as an uncombined element. Illustrate with examples.

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

Question 15 (6 marks)

Potassium has the electron configuration of 2,8,8,1 and Sulfur has the electron configuration 2,8,6.

(a) Write a half equation for each showing how the ions are formed in each case. [1]

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

(b) Identify the product formed when potassium reacts with sulfur to form an ionic compound and write its formula. [2]

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

(c) Predict the formula for the compound formed between Sulfur and X then identify the type of bonding present in the compound. [2]

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

Question 16 (5 marks)Describe the chemical bonding in sodium chloride. Explain how it leads to the compound having a high melting point, being hard and brittle, and being a non-conductor of electricity as a solid but a conductor as a liquid.

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................


Draw an electron dot diagram to represent a water molecule. [1]

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................


A particularly keen TheBrain student obtained water samples from the Dead Sea, whileholidaying in Jerusalem. He wanted to compare the percentage total salt of this seawater with that of his hometown’s. Using school equipment he determined the percentage of total salt in his Dead Sea water sample. The results of his analysis is detailed below:

mass of evaporating basin = 253.3 gmass of evaporating basin + seawater = 766.2 gmass of salt residue = 165.0 g

(a) Calculate the percentage composition of the seawater sample. Show yourworking. (3 marks)

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

(b) State one possible source of error for this determination. (1 mark)

..........................................................................................................................................

..........................................................................................................................................


Complete the table to illustrate the contrast between boiling and electrolysis of water in terms of physical & chemical change, breaking of a chemical bond or intermolecular forces and the relative amount of the energy required.

Boiling Electrolysis

Type of change

Type of forces broken

Magnitude of energy involved in the process(high/low)


A variety of chemical equations can be used to describe chemical reactions.

(a) Give a word equation for the chemical reaction that occurs when sulfur is strongly heated in oxygen. (1 mark)

……………………………………………………………………….....................................

(b) Give a balanced formulae equation for the reaction of sodium in water. (1 mark)

……………………………………………………………………….....................................

(c) Give the half equations for the reaction of iron metal with hydrochloric acid.(2 marks)

……………………………………………………………………….....................................

……………………………………………………………………….....................................


Refer to the table below to answer question 20.

SubstanceMP(0C)

Electrical conductivity

Solid state Liquid state

Q -102 Nil Nil

X 1423 Nil Conducts

Y 3600 Nil Nil

Z 1535 Conducts Conducts

(a) Which substance is iron? ……………………………………………..

(b) Which substance is calcium fluoride?……………………………………………..

(c) Which substance is dinitrogen trioxide?……………………………………………

(d) Which substance is diamond? ……………………………………………..

(e) For substance X, identify the type of particlethat carries the current in the liquid state………………………………………….

(f) For substance Z, identify the type of particlethat carries the current in the liquid state………………………………………….


Describe an industrial process that involves the separation of a mixture obtained from the atmosphere, hydrosphere or lithosphere. Hat properties are used to bring about the separation? In what ways (if any) does this process affect the environment?

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

..........................................................................................................................................

The Chemical Earth Topic Test

Documents

Transcript of The Chemical Earth Topic Test