chemistry paper 3 (practical) august /sept. 2013...

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1 E-resources available online at www.schoolsnetkenya.com / Email: [email protected] / Tel.: +254202319748 1 Name……………………………………………………………. Index No…………………………….. School…………………………………………………………… Candidate’s sign……………… Date………………………………… CHEMISTRY paper 3 (PRACTICAL) AUGUST /SEPT. 2013 Time: 2¼ Hours KCSE TRIAL EXAMINATIONS-2013 Kenya Certificate of Secondary Education (K.C.S.E) 233/3 CHEMISTRY PAPER 3 (PRACTICAL) Time: 2 ¼Hours INSTRUCTIONS TO CANDIDATES 1.Write your name and index number in the spaces provided. 2.Sign and write the date of examination in the spaces provided. 3.Answer ALL the questions in the spaces provided in the question paper 4.You are NOT allowed to start working with the apparatus for the first 15 minutes of the 2 ¼ hours allowed for this paper. This time is to enable you to read the question paper and make sure you have all the chemicals and apparatus required. 5.ALL working MUST be clearly shown where necessary 6.Mathematical tables and electronic calculators may be used. FOR EXAMINER’S USE ONLY QUESTION MAXMUM SCORE CANDIDATE’S SCORE 1 11 2 10 3 19 TOTAL 40

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Page 1: CHEMISTRY paper 3 (PRACTICAL) AUGUST /SEPT. 2013 …schoolsnetkenya.com/.../chemistry/chemistry-paper3-lainaku-2013.pdf · CHEMISTRY PAPER 3 (PRACTICAL) Time: 2 ¼Hours INSTRUCTIONS

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Name……………………………………………………………. Index No……………………………..

School…………………………………………………………… Candidate’s sign………………

Date…………………………………

CHEMISTRY paper 3

(PRACTICAL)

AUGUST /SEPT. 2013

Time: 2¼ Hours

KCSE TRIAL EXAMINATIONS-2013

Kenya Certificate of Secondary Education (K.C.S.E)

233/3

CHEMISTRY

PAPER 3

(PRACTICAL)

Time: 2 ¼Hours

INSTRUCTIONS TO CANDIDATES

1.Write your name and index number in the spaces provided.

2.Sign and write the date of examination in the spaces provided.

3.Answer ALL the questions in the spaces provided in the question paper

4.You are NOT allowed to start working with the apparatus for the first 15 minutes of the 2 ¼ hours

allowed for this paper. This time is to enable you to read the question paper and make sure you

have all the chemicals and apparatus required.

5.ALL working MUST be clearly shown where necessary

6.Mathematical tables and electronic calculators may be used.

FOR EXAMINER’S USE ONLY

QUESTION MAXMUM SCORE CANDIDATE’S SCORE

1 11

2 10

3 19

TOTAL 40

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This paper consists of 8 printed pages. Candidates should check the question paper to ensure

that all pages are p resent:

1, You are provided with ;

Solution F containing 3.65g of hydrochloric acid in 250cm3 of solution

Solution G containing 5.3gof a compound X2A in 250cm3 solution

You are required to determine the mass of A in the compound X2A

Procedure

1. Fill a burette with solution F

2. Using a pipette and pipette filler, place 25cm3 of solution G in a conical flask. Add two

drops of methyl orange indicator.

3. Titrate solution G with solution F and record your results in the table 2 below

4. Repeat the above procedure two more times and record the results.

Table 1

I II III

Final burette reading

(cm3)

Initial burette reading

(cm3)

Volume of F used (cm3)

(4mks)

(a) Calculate the:

(i) Average volume of solution F used.1mk ----------------------------------------------------

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(ii) Molar concentration of solution F. 2mk. (Cl=35.5, H=1.0)

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(iii) Concentration of solution G in g per litre 1mk

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(b) Given the ratio of reaction between solution F and G is 2:1

(i)Determine the molar concentration of solution G 2mks

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(ii)Determine the molar mass of solid G and hence work out the molar mass of A in the

compound X2A (X=23) 2mks

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2. You are provided with:

A solution containing 0.2M of ions of copper metal per litre of solution P.

0.6g of metal Q

0.3g of metal R

You are required to determine the heat of reaction between

(i)Metal Q and ions of metal P,

(ii)Metal R and ions of metal P,

And arrange the three metals in order of their reactivity.

Procedure

(1)Measure 40.0 cm3 of solution using a measuring cylinder and place it in the plastic

beaker provided.

(2)Measure the temperature t1 of this solution and record it in the table below.

(3)To the solution, add all metal Q provided, stir thoroughly with a thermometer and

determine the highest temperature as t2 reached. Record this temperature in the table 2

given below.

Table 2

Solution P+Q Solution, P+R

Highest temperature of mixture t1 (0C)

Initial temperature of solution t2 (0C)

Change in temperature ΔT (0C)

4mks.

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(a)Calculate the number of moles of ions of metal P in the 40.0 cm 3 of the solution.

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(a)Given that the heat change =MCΔT, where M=mass of solution, calculate the heat

change per mole of metal ions P when reacted with:

(i)Metal Q 2mks.

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(ii)Metal R 2mks

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(c)Arrange the three metals in order of their reactivity starting with most reactive

1mk.

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3. (a) Place a spatula end full of solid T in a boiling tube and add about 10cm3 of

distilled water and shake well the mixture. Divide the solution into four portions.

Observations Inferences

1mk

1mk

(a)To the first portion, add sodium hydroxide solution drop wise till in excess.

Observations Inferences

1mk

1½mk

(b)To the second portion, immerse a glass-rod into the solution and place the wet rod

into anon-luminous flame of a Bunsen burner.

Observations Inferences

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1mk 1mk

(c)To the third portion, add 3-dropes of lead( ii) nitrate and warm the solution.

Observations Inferences

1mk 1mk

(d)To the fourth portion, add a few drops of barium nitrate solution.

Observations Inferences

1mk 1½mks

3(b) You are provided with substance E. Carry out the following tests and record your

observations and inferences in the spaces provided

(i)to about 5ml. of E in a test tube add about equal amount of water and shake the mixture

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Observations Inferences

1mk 1mk

(ii)To about 2ml. of E on metallic spatula, ignite it in a non-luminous flame

Observations Inferences

1mk 1mk

(iii)To about 5ml. of E in a test tube add all the provided sodium carbonat

Observations Inferences

1mk 1mk

(iv) To about 5ml. of E in a test-tube add about 2ml. of concentrated sulphuric acid then

add about 5 ml. of ethanoic aci d. warm the mixture. Pour the mixture in a beaker

containing about 10ml of water.

Observations Inferences

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1mk 1mk

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