Chemistry Perfect Score Module Form 4 2011 No Logo

Form 4 Score A+ Module

CHEMISTRY SCORE A+ MODULE FORM 4

SET 1

1. The Structure of Atom 2. Chemical Formulae and Equations

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STRUCTURE OF THE ATOMS 1.

Matter is anything that …………………………………………………. and has ……………………. …………………….

2.

The particle theory of matter state that matter is ……………………………..…………………………

3.

Type of particle Example

4. Property Diagrammatic representation of the particles part icles in each of the physical states Arrangement of particles.

Solid

Liquid

Gas

Forces of attraction between particles Movement of particles Energy content

5.

Subatomic particles in an atom. Subatomic particle

6.

Symbol

Isotope are atoms with the same

Relative mass

Charge

………………………………………………… but different

…………………………………………………………………………………. 7.

The isotopes of an element have same ………………………………………….….. but different ………………………………… because they have ….………………………………………………




























9.

Complete the table below.

Isotope Carbon-14

Uses

Cobalt-60

Sodium-24

PAPER 2 : STRUCTURE 1. (a)

Diagram Diagra m 1.1 shows the results of an experiment experiment to investigat e the movement of bromine particles part icles in air.

Air

Gar jar Cover

Bromine vapour

Diagram 1.1

Reddish brown vapour spreads throughout throughout both gas jars within 10 minutes

Cover removed

(i)

State the name of the process involved in this experiment.

(ii)

………………………………………………………………………………………...…...……… [1 mark] State the type of particles present in bromine gas. ………………………………………………………………………………………….....……… [1 mark]

(iii)

Explain the observation in this experiment based on the kinetic theory of matter. ……………………………………………………………………………………….…...………




























Temperature

83 Diagram 1.2

R

T

Time, s (b)

Diagram 1.2 shows a graph gra ph of temperature against time when solid X is heated? (i) State the melting point of X.

(ii)

………………………………………………………………………………...………………… [1 mark] What happens to the temperature while the substance c hanges state? Explain. ……………………………….…………………………………………………...…………..…… …………………………………………………………………………………...…………...…… …………………………………………………...………………………………………...……… [2 marks]

(iii)

Explain the movement of particles X between R and T during heating. ……………………………………………………………………………………………...……… ……………………………………………………………………………………………...……… [2 marks]

Glass wool soaked in concentrated hydrochloric acid

Glass wool soaked in concentrated ammonia solution

Diagram 2 2.

Diagram 2 shows the set-up of apparatus appara tus to investigate the reaction between concentrated hydrochloric acid and concentrated ammonia solution to form substance X. Based on the information, answer the following questions.




























(ii)

Name substance X ……………………………..……………………………………………………………...……… [1 mark]

(iii)

Name the process occurs in the glass tube. …..………………………………………………………………………………………...……… [1 mark]

(b)

Which gas diffused faster? Why? …………………………..…………………………………………………………………...…….…… ………….…….………………………………………………………………………………...………. [2 marks]

(c)

Write the chemical equation for the reaction in the experiment. ……………………..…………………………………………………………………………...……… [1 mark]

3.

Table 3 shows proton number and nucleon number for atom W, X and Y. Atom

Proton number

Nucleon number

W

11

23

X

17

35

Y

17

37

Table 3

(a)

(b)

(i)

What is meant by proton number?

(ii)

.....................................................................................………………………………............... [1 mark] What is the number of neutron in atom W ?

......................................................................………………………………………................ [1 mark] Which atoms are isotopes? Explain why. ............................................................................................................................................................

(c)

........................................................................................................................................................... [2 marks] Write the electron electr on arrangement arra ngement of atom a tom X .




























(d)

(i)

Draw the electron arrangement of atom Y. In your diagram , show the number of proton and the number of neutron in the nucleus.

[2 marks] (ii)

What is the number of valence electron electro n of atom Y?

(iii)

..................................................................................................................................................... [1 mark] Write the formula of ion Y. ..................................................................................................................................................... [1 mark]

(e)

Write the symbol of atom X in the form of

A Z

X.

.............................................................................................................................................................. [1 mark] 4.

(a)

Diagram Diagra m 4.1 shows the set-up of an experiment to determine determi ne the melting point of solid X.

Thermometer

Water

Diagram 4.1

The temperature of X is recorded at 30 seconds intervals as shown below.

Time/second

0

30

60

90

120

150

180

210

70

77

80

80

80

82

85

95

o

Temperature/ C






























Graph temperature against time




























(ii)

On the graph that you have drawn in (a), label the melting point of substance

X.

[1 mark] (iii)

Explain why the temperature tempera ture remains constant from 60 s to 120 s? …………….……......................................................................................................................

(iv)

………….................................................................................................................................. [2 marks] o Draw the arrangement arra ngement of particles part icles in X at 85 C

[ 1 mark ] (b)

(c)

Why has the solid X in the boiling tube be stirred constantly consta ntly with the thermomet er during the experiment? …………………………….................................................................................................................... [1 mark] Why solid X is not directly heated without using water bath? …………..………………..................................................................................................................... [1 mark]

5.

Table 5 shows four substances and their respective formulae. Substance

Chemical formula

Iodine Copper Ethanol Potassium chloride

I2 Cu C2H5OH KCl Table 5




























PAPER 2 : ESSAY 6.

Diagram 6.1 shows an atom of an element based on the model by James Chadwick.

Electron Proton Neutron Diagram 6.1 (a)

Compare the relative mass and the charge of two of the subatomic subatomic particles in diagram 6.1. [4 marks]

7p 7n

Diagram 6.2 Diagram 6.2 shows an atom of element X. (b) (i) Describe Describ e fully the atomic structure struc ture shown in diagram 7.2. [4 marks] (ii)

Write a symbol for the element in the form of

A Z

(c)

Graph 6.3 shows the heating curve of element Y. o

Temperature / C

X

[2 marks]




























7

(a)

What is meant by “melting point”? During the melting of naphthalene, the temperature remains constant even though heat is applied. Explain why. [4 marks] Condensation is the process where a gas changes to its liquid state at a certain temperature and pressure when it is cooled.

(b)

Describe the change of the kinetic energy, arrangement and the forces of attraction between the particles at the following states: (i) (ii) (iii)

Before condensation During condensation After condensation [10 marks]

(c)

3+

Diagram 7 shows the electron arrangement of ion Y . e e

3+

e e e

14 n

e e

n e

neutron electron

e e e

Diagram 7

(i) Calculate the nucleon number of atom Y.

[2 marks]

(ii) Y reacts with oxygen to form oxide Y, with the formula Y2O3. The chemical equation for reaction Y with oxygen is show as: 4Y + 3O2  2Y2O3. Given that the relative atomic mass of Y = 27 and O = 16. Calculate the mass of oxide Y, Y O formed when 10.8 g Y is completely burnt in




























8.

A group of of students students set up the apparatus for an experiment experiment as shown in diagram 8. The result is is obtained obtained by the students are shown in table 8. Experiment A B C (a)

Observation After a few minutes the gar jar was filled with a reddish brown gas. After a few hours, the water turns purple. After a few days, the jelly turns purple.

State the aim of the experiments carried carr ied out. ……………………................................................................................................................................

(b)

State the hypothesis of the experiments. experiments . ……………………............................................................................................................................... ……………………...............................................................................................................................

(c)

State (i) The manipulated variable. variab le.

(ii)

……………………..................................................................................................................... The responding respond ing variable. …………………….....................................................................................................................

(iii)

The fixed variable of the experiments. experiments. …………………….....................................................................................................................

(d)

(e)

Based on the observat observation, ion, arrange the three states of mater mater in a sequence to show their speed in increasing order. …………………….............................................................................................................................. Based on the the rate of the movement movement of of the particles, describe describe the arrangement of of the particles in the






























CHEMICAL FORMULA AND EQUATION

1.

Write the chemical formula of the compound in the table below. Ion Sodium

Chloride

Nitrate

Hydroxide

Sulphate

Carbonate

oxide

Magnesium Lead(II) Copper (II) Iron (II) Iron (III) Aluminium 2.

Write balanced chemical equation for the following chemical r eactions. (a) Heat solid of copper (II) carbonate

(b)

…………………………………………………………………………………………. Nitric acid reacts with sodium hydroxide

(c)

…………………………………………………………………………………………. Hydrochloric acid reacts with zinc metal




























4.

5.

Calculate the number of moles of the following f ollowing substances. 23 (a) 6.0 x 10 aluminium

(b)

1.8 x 1021 argon

(c)

1.2 x 1023 bromine gas

(d)

2.4 x 10 carbon dioxide

(e)

3.0 x 1023 ammonia

20

Calculate the mass of following substances.

a) 1.5 mol of chlorine gas

b) 2.5 moles of oxygen gas

c) 2.0 moles moles of sulphuric acid

d) 0.5 moles of ammonia, NH3




























7.

Calculate the number of moles of the gases below. 3 (a) 250 cm of carbon dioxide in room temperatur e.

(b) 500 cm3 of hydrogen sulfide at STP.

3

(c) 200 cm of hydrogen chloride in room temperature.

(d) 750 cm3 of neon in room t emperature.

(e) 300 cm3of ammonia at STP.

8.

Magnesium powder reacts with hydrochloric acid to produce salt and hydrogen gas. (a) Write the balance chemical equation for this reaction.

(b)

…………………………………………………………………………………………. If 2.4 g of magnesium powder is added into excess hydrochloric acid, calculate, (i) The mass of salt formed.




























10.

Excess sodium carbonates is added into 50 cm 3 of 0.5 mol dm-3 copper(II) chloride. The chemical equation for for the reaction is is as follows: CuCl2 +

11.

Na2CO3



NaCl

+

(a)

Balance the chemical equation for the reaction.

(b)

Calculate the mass of copper(II)carbonate c opper(II)carbonate..

CuCO3

5g of calcium carbonate is added to excess hydrochloric acid. (a) Write balanced chemical equation for the r eaction. ……………………………………………………………………………………….……. (b) Determine the volume of carbon dioxide gas evolved at room temperature

12.

When sodium bicarbonate is heated, it decomposed to sodium carbonate, carbon dioxide and water.




























Concentration of acids and alkalis (STOICHEIOMETRY)

The concentration of a solution is the mass (in gram) or the number of mole of solute dissolved in a solvent 3 to form 1.00 dm of solution. Concentration, g dm-3

Mass of solute, g Volume of solution , dm 3 Number of mole of solute, mol Volume of solution , dm3

-3

Concentration, mol dm / molarity

Titration Formula

Ma Va a

= Concentration of the acid, = Volume of used acid, = the number of mole of acid,

MaV2 =

a

MbVb

b

Mb Vb b

= Concentration of the alkali = Volume of used alkali = the number of mole of alkali

Dilution M1V1 = M2V2 13.

3

-3

100cm of HCl 2.0 mol dm reacts completely with excessive zinc powder. C alculate the






























15.

X g sodium carbonate reacts completely with 100 cm3 hydrochloric acid -3 1.0 moldm to produce sodium chloride, carbon dioxide and water. Find X. (relative atomic mass: Na =23, C = 12, O = 16)

16.

10 g of copper(II) oxide oxide reacts react s completely completel y with 100 cm hydrochloric hydrochloric acid to form copper(II) chloride and water. Calculate the molarity of acid used. (JAR Cu =64, =64, O = 16 )

17.

The concentration of sodium hydroxide solution is 8.0 g dm -3. (a) What is the molarity of the solution?

3




























PAPER 2: STRUCTURE 1.

Diagram 1 shows the set-up of the apparatus for an experiment to determine the empirical formula of an oxide of copper.

Oxide of copper

Dry hydrogen gas

Heat




























(c)

Describe Describ e the steps that should be taken to ensure that all the air in in the combustion combust ion tube has been expelled , before any heating is carried out. …………………………..…………………………………………..………………………… . ……………………………….……………………………………………………………… ……………………………………...………………………………………………………… [3 marks]

2.

(a)

Culculate the relative molecular or formula masses of the following substances. (i) Ethanol, C 2H5OH. Given that relative atomic mass of H = 1, C = 12, O = 16.

[1 mark]




























A student heats 8.28 g silver carbonate. Calculate the volume of carbon dioxide gas, CO2 collected at room temperature. Given that relative atomic mass of C = 12, O =16, Ag = 108,

[3 marks] 3.

Diagram 3 shows 3.1 g of copper (II) carbonate being heated strongly in attest tube. The gas given out is passed into limewater in a test tube through a delivery tube.

Copper(II) carbonate




























PAPER 2 : ESSAY

4. (a)

The information below is regarding substance X



Carbon 85.70%



Hydrogen 14.30%



Relative molecular mass = 56






























PAPER 3 : STRUCTURE 5.

A student carried out an experiment to determine the empirical empirical formula of magnesium oxide. The steps and set-up of apparatus of the experiment are shown in Diagram 5. 1. The crucible and lid are weighed.




























(a)

Complete the following table by stating the observations and related inferences in the experiment. Observations

(i) ................................................

Inferences

(i) ................................................................























































PERIODIC TABLE OF THE ELEMENTS Periodic Table of Elements 1

2

13 14 15 16 17 18




























Group 18 : Noble Gas

He Ne

2 2. 8

stable / duplet electron electr on arrangement arra ngement




































































































































































































































































































































































































































































































































































































































































































































































































11.

Write an equation of dissociation for t he following acid. a) Nitric acid : ...............................………………………………………………………… ...............................…………………………… …………………………………………… ……………… b)

Ethanoic acid : ...............................………………………………………………………… ...............................…………………………… …………………………………………… ………………

c)

Carbonic acid : ...............................……………………………………………… ...............................…………………………… ………………………………………… ………………………… …

d)

Sulphuric acid : ...............................………………………………………………………… ...............................…………………………… …………………………………………… ………………

e)

Chemical properties of acid. Reaction

With reactive metal

Product

Salt and hydrogen gas

Example and Chemical equation Zn + 2HCl  ZnCl2 + H2

PAPER 2 : STRUCTURE

1.

An experiment is carried out in the laboratory to determine the end point of the reaction between 25.0 3 -3 cm of potassium hydroxide solution and 1.0 moldm of sulphuric acid. Phenolphthalein is used in the titration to detect the end point of the reaction. diagram 1 shows the set-up of apparatus for the titration.

Sulphuric acid -3 1.0 moldm




























The volume of sulphuric acid added and the change of the colour of potassium hydroxide solution shown in the Table 1 below. Volume of sulphuric acid (cm3) Colour of potassium hydroxide solution

4,5

4.6

4.7

4.8

4.9

5.0

5.1

Pink

5.2

5.3

Colourless

Table 1

(a)

Name the chemical reaction between potassium hydroxide solution a nd sulphuric acid.

(b)

…………………………..................……………… …………………………..................……………………………………… ……………………………… ……… [1 mark] Write a chemical equation for the reaction. ………………………………................……………… ………………………………................……………………………………… ……………………………. …….

(c)

[1 mark] Write the formula of ions which are present in t he conical flask when the volume of s ulphuric acid added is: 3 (i) 4.5 cm ................................................................................................................................... (ii)

5.0 cm3 ................................................................................................................................... [2 marks]

(d)

3

What is the volume of sulphuric acid needed to neutralise 25 cm potassium hydroxide solution? …..................................................................................................................................... [1 mark]

(e)

Calculate the concentration of potassium hydroxide solution in this experiment.

[2 marks] (f)

If sulphuric acid is replaced with nitric a cid with the same molarity, predict 3 the volume of nitric acid require to n eutralise 25.0 cm of the the potassium hydroxide solution. Explain why.




























Experiment I and II are carried out. Table 2 below shows the results of the experiment.

Observations Experiment Solution X

Solution Y

I

Marble chips added into solutions

Gas bubbles

No changes

II

Electrical conductivity

Deflection of ammeter reading

No deflection of ammeter reading

Table 2

a)

Name a suitable solvent to produce (i) Solution X

(ii)

..................................................................................................................................... Solution Y ..................................................................................................................................... [2 marks]

b)

(i)

(ii)

Which solution shows acidic properties ................................................................................................................................. What is the role of the solvent used to produce the acid in (b)(i) ................................................................................................................................. ................................................................................................................................. [2 marks]

c)

(i)

(ii)

Name the gas produce in Experiment I ................................................................................................................................ Describe a chemical test to verify the gas in (c)(i). ................................................................................................................................. ................................................................................................................................ [3 marks]

d)

Solution X can conduct electricity but solution Y cannot. Explain this statement. .......................................................................................................................................... ..........................................................................................................................................




























3.

Table 3, below shows the pH value of four solutions. The solutions are of the same concentration Solution

W

X

Y

Z

pH

1

5

7

14

Table 3

a)

(i)

Name one example of solution Z.

(ii)

................................................................................................................................. Write a chemical equation for for the reaction of Z in a(i) a(i) with with sulphuric acid. .................................................................................................................................

(iii)

Name the chemical chemical reaction occur in a(ii). ................................................................................................................................. [3 marks]

b)

Which solution possibly can be sodium sulphate? .......................................................................................................................................... [1 mark]

c)

(i)

(ii)

Which solution can change a blue litmus paper to red? ................................................................................................................................. State one test to prove the chemical chemical property of c(i) c(i) without without using an indicator. ................................................................................................................................. ................................................................................................................................. …………………………………………………………………………………….

[3 marks] d)

Explain why solution W and Solution a nd solution X have different pH val ues. ..................................................................................................................................... ..................................................................................................................................... [2 marks]




























Dry hydrogen chloride gas

Filter funnel

Methyl benzene ` Beaker A

Dry hydrogen chloride gas

Filter funnel Water

Beaker B

4.

Figure above shows the arrangement of apparatus used to prepare hydrogen chloride in methyl benzene and in water respectively. resp ectively. a) What is the purpose of using filter funnels funnels in this experiment experiment ? ................................................................................................................................................ [1 mark] b)

(i)

What is observed when a piece of magnesium magnesium ribbon is placed in Beaker A and Beaker B respectively. Beaker A : .................................................................................................................

(ii)

Beaker B :................................................................................................................. State the reason for your answer in b(i) ................................................................................................................................... ................................................................................................................................. [3 marks]

c) Name the types of particles present in






























d) Water is added to the solution i n Beaker A and the mixture is then shaken. W hen sodium carbonate solution is added, effervesence occurs. (i)

Name the gas and suggest a suitable suitable test to identify the gas evolved. evolved.

(ii)

................................................................................................................................ State the role of water that caused t he liberation of the gas.

(iii)

................................................................................................................................. Write the ionic equation for the rea ction involving the liberation o f the gas. .................................................................................................................................. [3 marks]

5.

Diagram 5 shows four test tubes contain dry glacial ethanoic acid, aqueous solution of dilute hydrochloric acid and aqueous solutio n of X.

Dry glacial ethanoic acid Blue litmus paper P

Aqueous solution of ethanoic acid 0.1 moldm-3

Dilute hydrochloric acid

Blue litmus paper

Blue litmus paper Q

Aqueous solution of X

R

Diagram 5

a)

(i)

State the colour change of the litmus paper in test tubes Q and R.

S

ethanoic acid,




























c)

Table 5 shows the pH value of aqueous solution of ethanoic acid and of the same molarity. Type of acid

Molarity pH value

aqueous solution of ethanoic acid 0.1 moldm moldm-3 3.0

dilute hydrochloric acid

dilute hydrochloric acid

0.1 moldm-3 1.0

Table 5 Explain why the pH value of aqueous solution of ethanoic acid is higher than the pH value of dilute hydrochloric acid. .............................................................................................................................................. .............................................................................................................................................. .............................................................................................................................................. d)

[2 marks] Calcium carbonate powder is added into test tube R. Write the chemical chemical equation for the reaction that takes place. .................................................................................................................................................. [1 mark]

e)

Aqueous solution of X is an acidic solution. As a chemistry student, describe briefly how you are able to prove that X is an acidi c solution. You are not allow to use lit mus paper, pH meter or any indicators. Procedure:

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




























6.

(a)

A student carried out an experiment to study the pH of a few aqueous solutions using pH The results were tabulated below. Aqueous solution

P

Q

R

S

T

U

pH

13

7

4

8

20

1

paper.

Table 6

Which of the solution in the table above could be (i)

Distilled water

(ii)

…………………………………………………………………………….………… Vinegar ……………………………………………………………………………….………

(iii)

Sodium hydroxide …………………………………………………..…………………………………...

(iv)

Hydrochloric acid ………………………………….……………………………………………...……. [4 marks]

b)

(i)

An apple contains maleic maleic acid C4H8O5 which which is a weak acid, What is meant by weak acid ? ……………………………………………………………………………….………

(ii) The pH of 1.0 mol mol dm-3 maleic acid solution is higher than hydrochloric acid with the same concentration. Explain why. …………………………………………………………………………...…………..




























PAPER 2: ESSAY

7.

(a)

(i)

What is meant by ‘standard solution’ ?,

[1 mark] (ii) Describe how 100cm of 2.0 moldm sodium hydroxide solution can be prepared in the school laboratory, Your description should include the calculation Use the information, Relative atomic mass of Na = 23, O =16 , H = 1 [7 marks] -3 Using the 1.0 mol dm sodium hydroxide solution from (a) above. Describe how you would determine the unknown concentration of a sample of hydrochloric acid, HCl using the titration method. 3

(b)

-3

You may use either methyl orange or phenolphthalein as indicator. Include, in your answer, the chemical equation and calculation. [12 marks] 8.

(a)

The following information is about sodium hydroxide solution and ammonia solution. 

pH of sodium hydroxide solution 1.0 mol dm-3 is 14



pH of ammonia solution 1.0 mol mol dm is 10

-3

Explain why both solutions have different pH value. [6 marks] (b)

The label of a reagent bottle was dirty caused by a chemical substance. substance. The reagent is suspected suspected to contain dilute hydrochloric acid. Describe two chemical tests which can be used to identify the chemical chemical solution is dilute hydrochloric acid.

solution if the [8 marks]

(c)

Glacial ethanoic ethanoic acid acid does not release any gas gas when it is poured into pieces of calcium calcium carbonate. However, effervescence occurs when several drops of water are added into the mixture of ethanoic




























PAPER 3: STRUCTURE

9.

Diagram 9 shows the results of titration between sulphuric acid and sodium hydroxide solution.

1.0 mol dm-3 Sulphuric acid, H2SO4

Initial reading

Final reading

25.0 cm3 sodium hydroxide, NaOH solution + phenolphthalein DIAGRAM 9

(a)

Based on the diagram 2, record record the final and initial burette readings of the burette.

Final reading

=

…………………. cm3






























(c)

(d)

(i)

State the colour change in the solution.

(ii)

……………………………………………………………………………………… [3 marks] State the inference of the colour change.

…….………………………………………………………………………………… [3 marks] Write the operational definition for the neutralisation. …………………………………………………………………………………………… …………………………………………………………………………………………… [3 marks]

(e)

You are given three examples examples of acids; sulphuric acid, ethanoic ethanoic acid and and hydrochloric acid. Classify them into monoprotic and diprotic acids.

[3 marks] (f)

Based on the titration results, calculate the molarity of sodium hydroxide solution used used . Given the chemical equation for the neutralisation is as follow:




























Diagram 10, shows the initial and final burette readings for both experiments. Experiment 1

0

20

1

21

Initial burette reading

Final burette reading

Experiment II

15

25




























(c)

The chemical equation for the reaction in the experiment is : HX +

NaOH



NaX

+

H2O

Calculate the concentration of HX acid solutions used in both experiments. (i)

Experiment I

(ii)

Experiment II

[ 3 marks] (d)

State the hypothesis in this experiment.

…………………..……….............………………………………………………………… .......………………………………………………………………………………………… [ 3 marks] (e)

If HX acid is replaced replaced with sulphuric acid of the same concentration, it is found found that the volume of the sulphuric sulphuric acid used in the titration is half of the volume of HX acid. why.

Explain




























SALTS 1.

A salt is an ionic compound that is

formed when the ………………………… … ion in +

an acid is replaced by a …………………………………… ion or ammonium ion (NH4 ). 2.

Solubility of salts. Type of salt Sodium, potassium and ammonium salts Nitrate salts

Solubility in water All are soluble.

Sulphate salts Chloride salts Carbonate salts

3.

Preparation of soluble salts. Preparation of soluble salts An acid reacts with reactive metal.

Example / Reactants Magnesium and hydrochloric acid

Chemical equation Mg + 2HCl  MgCl2 + H2




























5.

Quantitive analysis of salts. (a) Colour of salts Colour White or colourless

Solid

Solution

Sodium,potassium,magnesium,, ammonium, Sodium,potassium,magnesium

Na+,K+,Mg2+,

Lead ,chlorides, sulphates,nitrates.

Pb2+, Zn2+, NH4+

Green

Blue

Brown

(b)

Action of heat on Carbonate and Nitrate salts. Type of salt

Colour of salt before heating

Colour of residue Hot

Copper (II) carbonate

Cold






























(c)

Test for Anions.

Summarise the tests used to identify anions in the table below. Anion

Test

Carbonate, CO32-

Add 2 cm hydrochloric acid, bubble the gas produced through lime water.

Observation and inference

3

Chloride, Cl Sulphate, SO42Nitrate,

White precipitate is formed, sulphate ion is present.




























PAPER 2: STRUCTURE

Oxide M

Compound J

(Brown when hot, yellow when cooled) Heat

+ dilute nitric acid

+ Gas L (Colourless)




























(e)

Describe a confirmatory test which you can use to differentiate the cations you named in (d). ........................................................................................................................................................... ........................................................................................................................................................... ........................................................................................................................................................... ........................................................................................................................................................... [4 marks]

2.

An experiment to investigate the effect of heat on solid lead (II) carbonate is shown on diagram 2. Boiling tube




























(b)

The result of the experiment is shown in Table 2. [Relative atomic mass: Pb=207, C=12, O=16; 1 mol of gas occupies 24dm3 at room temperature and pressure] Substance Mass of boiling tube Mass of boiling tube and lead (II) carbonate before heating heatin g Mass of boiling tube and residue after heating Table 2

(i)

Calculate the mass lead (II) carbonate used.

Mass (g) 12.45 23.13 22.56




























3.

Diagram 3 shows the formation of zinc nitrate and its conversion to other substances + dilute nitric acid

W

Zinc nitrate

Nitrogen dioxide + Gas X

+ dilute NaOH (aq) + potassium iodide solution

+ sodium carbonate solution

Y + sodium nitrate R + sodium nitrate






























(d)

When potassium iodide is added to zinc nitrate solution a precipitation precipitation takes place. (i) Name the substance Z

(ii)

………………………………………..……………………………………………………… [1 mark] Write an ionic equation to show how Z is produced.




























5. (a)

Lead (II) sulphate is insoluble in water. Describe the preparation of lead (II) sulphate in the laboratory. In your description, include the reagents an d chemical equation involved. [10 marks]























































7.

Diagram shows two containers, containing colourless solution labelled A and B.
















































































































































































































































































Chemistry Perfect Score Module Form 4 2011 No Logo

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