Chemical Reaction Work Sheet

8/10/2019 Chemical Reaction Work Sheet

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Chemical Reaction

1.

Why do potato chips manufacturers fill the packet of chips with nitrogen gas?2.

A student has been colleting silver and copper coins. ne day he observed that a black coating on

silver coins and a green coating on copper coins. !ive the chemical names of the black and greencoatings. "ow are they formed?

#.

$ap water conducts electricity whereas distilled water does not. %&plain' Why?

(.

)ive metals A' *' C' + and ) are added to the following solutions one by one. $he observations madeare below ,

-etalron/0sulphate

Copper/0 sulphateincsulphate

ilvernitrate

Aluminiumsulphate

A 3o reactionReddish browndeposit

Coating onit

Coating onit

444

* !rey deposit 4443oreaction

Coating onit

444

C 3o reaction 3o reaction3oreaction

Whitedeposit

444

+ 3o reaction 3o reaction3oreaction

3o reaction 3o reaction

% 444Reddish browndeposit

3ewcoating

3ewcoating

3o reaction

Answer the following 5uestions based on above observations4i.

Which is the most active metal and which is the least reactive? Why?ii.

What would be observed when /a0. * is added to a solution of copper /0 sulphate and /b0. % isadded to the solution of iron sulphate? %&plain' why?

ii.

Arrange the metals A' *' C' + and % in order of increasing reactivity.

v.

Container of which metal can be used to store both 6inc sulphate solution and silver nitrate solution.v.

Which of the above solutions can be easily stored in a container made up of these metals?

7.

dentify the type of chemical reaction taking place in each of the following8

i.

*arium chloride solution is mi&ed with copper sulphate solution and a white precipitate is formed.ii.

n heating copper powder in air in a china dish' the surface of the copper powder turns black.

ii.

n heating green coloured sulphate crystals' reddish brown solid is left and smell of gas havingodour of burning sulphur is e&perienced.

v.

White silver chloride turns grey in sunlight.

v.

*arium hydro&ide reacts with ammonium chloride solution to give ammonia' barium chloride andwater.

vi.

ron nails when left dipped in blue copper sulphate solution become brownish in colour and the bluecolour of copper sulphate fades away.

ii. 9uick lime reacts vigorously producing a hissing sound with water releasing a large amount of heat.:.

What is the colour of ferrous sulphate crystals? "ow does this colour change after heating? 3ame theproducts formed on strongly heating ferrous sulphate crystals. What type of chemical reaction occursin this change?

;.

What is an o&idation reaction? !ive an e&ample. s o&idation an e&othermic or endothermic reaction?.

Write a balanced chemical e5uation for the reaction which is used in black and white photography.11.

n electrolysis of water' why is the volume of gas collected over one electrode is double that of gascollected over the other electrode?


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12.

What is observed when a solution of potassium iodide is added to a solution of lead nitrate taken in atest tube? What type of reaction is this? What is the colour of the product formed? Write a balancedchemical e5uation to represent the above reaction.

1#.

Crystals of copper sulphate are heated in a test tube. What is the colour of the copper sulphatecrystals before and after heating? What is the source of li5uid droplets seen on the upper inner sideof test tube during heating?

1(.

tate which of the chemical reactions will take place or not' giving suitable reason for each 8

n /s0 Cu(/a50 444444@ n(/a50 Cu /s0)e /s0 n(/a50 444444@ )e(/a50 n /s0n /s0 )e(/a50 444444@ n(/a50 )e /s0

17.

Why do ionic compounds conduct electricity in a5ueous solution and not in solid state?1:.

dentify the type of chemical reaction in

3a2(/a50 *aCl2/a50 444444@*a(/s0 3aCl /a50.

1;.

What happens to the crystals of sodium carbonate' if they are /i0. left open in air' /ii0. heated? Write

chemical e5uations to support your answer.1.

*alance the following chemical reactions 8

21.

What are the decomposition reaction' combination reaction' precipitation reaction' endothermicreaction' e&othermic reaction' thermal decomposition reaction' displacement reaction and doubledisplacement reaction? %&plain each with one e&ample?

22.

A person wanted his house to be whitewashed. "e bought 17 g of 5uick lime and dissolved it in #>liters of water. n adding lime to water he noticed that the water started boiling even when it was notbeing heated. "ive reason for his observation. Write the corresponding chemical e5uation and nameproduct formed.

2#.

Which one of the following reaction is combination reaction 8

/a0 a magnesium wire is burnt in air'/b0 limestone is heated'/c0proteins are converted into amino acids and/d0 electricity is passed through water.

2(.

Which type of reactions are represented by the following e5uations8

27.

What are redo& reactions? %&plain with e&ample.2:.

A student dropped a few pieces of marble in dilute hydrochloric acid contained in a test tube. $heinvolved gas was passed through lime water. What change would be observed in lime water? Writebalanced chemical e5uation for both the changes observed.

2;.

What is meant by photochemical decomposition? %&plain with an e&ample.


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2


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ii. "ow does it help in e&tinguishiiii. s the p" value of baking soda

7.

+ry "Cl gas does not turn blue lit

:.

A student drooped few pieces ofevolved gas was passed throughbalanced chemical e5uation when

;.

Answer the following 5uestions 8i. Why is the formula of Dlaster owater molecule attached to Ca(ii. Why is sodium bicarbonate an eiii. odium bicarbonate is an esse

iv. When electricity is passed thrthis process is called chlor4alkali p

.

!ive reasons for the following 8

g fire?solution lower than or higher than ;?

us red whereas hydrochloric acid does. !

marble in dilute hydrochloric acid conta ime water. What change would be observ/i0 gas was evolved /ii0 gas was passed thro

Daris written as Ca(.F"2? "ow is it

ssential ingredient of most antacids?tial ingredient of baking powder. What is

ugh a5ueous solution of 3aCl' three pro rocess?

hanges into curd' will its p" value increas

rom gypsum has the property of hardenthe compound. Write the chemical e5uatios?he p" of mouth is lower than 7.7?ncentration of hydrogen ion in a solutio

higher concentration of "ions than 1-mula of calcium compound used for disied?ontainers? Containers made from which

owder? !ive chemical reaction involved.baking powder?

e on changing " concentration? "ow do

8 a. A metal compound GAH reacts withinguishes a burning candle. Write balanceds formed is calcium chloride.cidic characters in a5ueous solution whilew acidic characters?

onium ion affected when a solution of anarbonate is heated? Write the balanced che

the p" of A is : and the p" of * is


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i. While diluting an acid' it is recommended that the acid should be added to the water and not waterto acid.ii. +ry ammonia has no action on litmus paper but a solution of ammonia in water turns red litmus

blue.iii. Dlaster of Daris should be stored in a moisture proof container.

iv. +istilled water does not conduct electricity whereas rain water does.

v. Curd and sour substances should not be kept in brass or copper vessels.vi. *leaching powder pollutes when left open air.

vii. Acetic acid is a weak acid while hydrochloric acid is a strong acid.viii. odium carbonate is regarded as a basic salt.

21.

RaIesh took sulphur powder on a spatula and heated it. "e collected the gas evolved on lowering atest tube over it.

/a0. What will be the action of gas ini. dry litmus paper

ii. -oist litmus paper./b0. Write balanced chemical e5uation for the reaction.

22.

What are the special properties of plaster of Daris' which makes it useful in hospitals?

2#.Which one of the medicines 8 antibiotic' analgesic' or antacid is used for treating indigestion?2(.

)ive solutions A' *' C' + and % when tested with universal indicator showed p" 7' 2' 1>' ; and 12respectively. Arrange the p" in increasing order of hydrogen ion concentration.

27.

Eou must have seen tarnished copper vessel being cleaned with lemon and tamarind Iuice. %&plainwhy these sour substances are effective in cleaning the vessels.

2:.

An element reacts with o&ygen to give a compound of high melting point. $his compound is highlysoluble in water. s this element carbon' calcium' silicon or iron?

2;.

Which gas is produced in when dilute "Cl is added to a reactive metal? Write chemical e5uation

when iron reacts with dilute sulphuric acid.2


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(7.

Write the name and the chemical formula of organic compound which is present in vinegar.

(:.

3ame an acid base indicator prepared at home. Which acid is present in vinegar' sour milk or curd'tamarind' lemon' orange and ant sting.

(;.

What is the colour of methyl orange in baking soda solution?(.

What is a5ua regia? 3ame the metals which are soluble in it.71.

What do all/i0. Acids'/ii0. *ases have in common? What is milk of magnesia? s it a strong or mild base?

72.

Which chemical compound is present in our tooth enamel? s toothpaste acidic or alkaline?7#.

Which will have more " ion concentration 8 a solution with p"J> or a solution with p"J1(?

7(.

Which acid and base are used in the formation of 8 Cu(' 3a3#' 3a"C#' and 3a"(?77.

What is the role of tartaric acid or citric acid present in baking powder?

7:.

3ame an indicator which indicates the various levels of the " ion concentration.7;.

When the concentrated a5ueous solution of a substance GKH is electrolysed sodium hydro&ide'chlorine and hydrogen gas are produced. 3ame the substance GKH. What is the special name of thisprocess?

7.

A gas highly soluble in water turns colorless solution to pink when a few drops of phenolphthaleinsolution is added to it. What is the nature of the gas?

:1.

tate for what purpose is bleaching powder used in water treatment plants.

:2.

A compound GEH loses water of crystalli6ation when e&posed to air. dentify compound and write itsformula.

:#.

A calcium compound yellowish white in colour is used as disinfectant and also in te&tile industry.3ame the compound. "ow is it prepared? !ive chemical reaction involved.

:(.

When phenolphthalein was added to a solution of GKH' it turned pink. After some time pink colourfades away. dentify GKH and give reason for the observation.

:7.

+efine natural' synthetic and olfactory indicators with two e&amples each.

::.

What are the substances called which are used to prevent o&idation?

:;.

"ow will you provide the following information in a chemical reaction 8 a5ueous solution' a li5uid'evolution of heat' evolution of gas' steam and precipitation?

Chemical Reaction Work Sheet

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