2010 KCSE Chemistry Trial P1-001

2010 KCSE Chemistry Trial P1-001

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

School………………………………………………………                   Date ………………………….…

Candidate’s Signature…………………………………….

233/1

CHEMISTRY

Paper 1

July/August 2010

2 hours

RARIEDA DISTRICT JOINT EVALUATION TEST – 2010

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

233/1

CHEMISTRY

Paper 1

July/August 2010

2 hours

INSTRUCTIONS TO CANDIDATES.

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

2.      all working must be clearly shown

3.      Mathematical tables and electronic calculators may be used.

FOR EXAMINER’S USE ONLY.

QUESTION MAXIMUM SCORE CANDIDATES SCORE
1 – 30 80

This paper consists of 16 printed pages.

Candidates should check the question paper to ensure that all pages are printed as indicated

and no questions are missing

1.         Study the diagram below and answer the questions that follow. The diagram shows the method of separating components of mixture Q.

2010 KCSE Chemistry Trial P1-001

(i)         State the role of the part labeled X.                                                                            (1mk)

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

………………………………………………………………………………………………………

(ii)        State what would happen if the water inlet and water outlet in the Liebig’s condenser is interchanged?                                                                                                              (1mk)

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

………………………………………………………………………………………………………

2.         a)         Define Gay – Lussac’s law.                                                                                        (1mk)

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

………………………………………………………………………………………………………

b)         30cm3 of ethane were mixed with 100cm3 of oxygen and the mixture was sparked to complete reaction. If all the volume were measured at a pressure of one atmosphere and a temperature of 25°C, Calculate the volume of  the  residual gas under.

State condition.                                                                                                           (2mks)

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

………………………………………………………………………………………………………

………………………………………………………………………………………………………

3.         You are given the following half equations

2010 KCSE Chemistry Trial P1-001

a)         Write an overall equation for the cell reaction.                                                           (1mk)

b)         Calculate the Eө value of the cell.                                                                               (1mk)

c)         Name the oxidizing agent.                                                                                          (1mk)

………………………………………………………………………………………………………

4.         The diagram below shows a diagram of non – luminous flame. A piece of white paper is

slipped into the region of the flame as shown in the  diagram and quickly removed before it catches fire.

2010 KCSE Chemistry Trial P1-001

a)         Draw and label the piece of paper to show how it is affected by the above flame.   (2mks)

b)         Explain why a luminous flame of a bunsen burner produces bright yellow light.      (1mk)

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

………………………………………………………………………………………………………

5.         A student added 50 cm3 of 1.0m aqueous sulphuric acid to 50cm3 of 2.0M potassium hydroxide and the temperature rose by 4°C.

a)         Define the term molar heat of neutralization.                                                             (1mk)

b)         Calculate the molar heat of neutralization. (C = 4.2 kJk-1 density of solution = 1g/cm3.

(2mks)

6.         Study the set –up below and answer the questions that follow.

a)         Identify the gas produced in the flask.                                                                       (1mk)

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

b)         Using an equation explain the observation made in the boiling tube.                        (2mks)

2010 KCSE Chemistry Trial P1-001

7.         Write the structure of the polymer.

(i)         formed by the following monomer.                                                                            (1mk)

2010 KCSE Chemistry Trial P1-001

(ii)        Give the IUPAC name of the following organic compound.                                     (1mk)

CH2 (CL) CH2 (CH3) CH2CH2CH3

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

8.         The set – up below was used by a student to try to prevent the rusting of an Iron rod.

2010 KCSE Chemistry Trial P1-001

(a)        Did the student succeed in preventing the rusting of Iron using the set – up above?            (2mks)

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

………………………………………………………………………………………………………

………………………………………………………………………………………………………

b)         Which method of rust prevention was the student investigating?                             (1mk)

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

9.         In an experiment 30g of metal carbonate were added to 30cm3 of 1 M hydrochloric acid in a beaker. Mass of the beaker and its contents were weighed at time intervals.

a)         Sketch a graph on the axis given below and labeled it as Q.                                      (1mk)

2010 KCSE Chemistry Trial P1-001

b)         On the same axis sketch another graph when 2M of the acid is used with the same mass of the carbonate.

c)         State an apparatus that is used to determine the rate of a reaction in this experiment.(1mk)

………………………………………………………………………………………………………

………………………………………………………………………………………………………

10.       The chromatogram below shows the constituents of ink sample M using methylated spirit as solvent.

2010 KCSE Chemistry Trial P1-001

a)         Describe how you would obtain a solid sample of the red pigment from the chromatogram above.                                                                                                                                    (2mks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

11.       Study the energy level graph for reactants and products during a chemical reaction representing the equation below.

2010 KCSE Chemistry Trial P1-001

a)         What will be the effect of increasing temperature to the above reaction?

Explain.                                                                                                           (1 ½ mks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

b)         How would a decrease in pressure affect the amount of hydrogen?             ( 1 ½ mks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

12.       Calculate the number of hydrogen ions in 5cm3 of 0.5 molar phosphoric acid. (L = 6.0 x 1023)

(2mks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

13.       Study the flow chart below and answer the questions that follow.

2010 KCSE Chemistry Trial P1-001

a)         Identify ;

i)          Solid B                                                                                                                        ( ½ mk)

ii)         White precipitate E                                                                                                     ( ½ mk)

iii)        The substance responsible for the colourless solution G.                                            ( 1mk)

b)         Write the ionic equation for formation of precipitate F.                                             ( 1mk)

14.       The following table shows the pH values of solutions A, B, C and D.

Solution A B C D
pH 3 7 10 14

(i)         Which solution is likely to be that of iron (III) Chloride?                                          (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

(ii)        Which solution has the highest concentration of hydroxide ion? Explain.                (2mks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

15.       The diagram below shows a structure (i) of water molecules

2010 KCSE Chemistry Trial P1-001

i)          Name the bonds labelled                                                                                ( ½ mk)

a) ………………………………………………………………………………………….

……….……………………………………………………………………………………

b…………………………………………………………………………………………..

……………………………………………………………………………………………

ii)         Using dots (.) and cross(x) diagram show the bonding in the compound phosphonium ion

PH4+ (H = 1, P = 15)                                                                                       (2mks)

16.       M grams of radioactive isotope decayed to 5g in 90 days. The half – life of the isotope is 30 days

(a)        What is half – life?                                                                                                      ( 1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

(b)        Calculate the initial mass of M of the radioactive isotope.                                         (2mks)

17.       A form one student set – up the apparatus below to investigate the property of steam on aluminium.

2010 KCSE Chemistry Trial P1-001

(a)        Explain why no gas was collected in the above set –up.                                            (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

(b)        Aluminium reacts with steam to form aluminium oxide and not aluminium hydroxide as expected. Explain.                                                                                                           (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

( c)       Explain why the reaction between aluminium and steam stops after a short time.

(1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

18.       The table below shows properties of some elements. Study it carefully and answer the questions that follow.

Element Sodium Magnesium Phosphorus
Electrical conductivity Good Good Poor
Melting point 98 660 44 44 or 115

a)         Suggest why phosphors has been a signed two melting point values.                        (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

b)         Explain why the melting point of magnesium is higher than that of sodium.            (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

19.       1.512g of metal carbonate XCO3 reacts with 20cm3 of 1.8M hydrochloric acid completely.

Calculate the relative atomic mass of element X. (C = 12, O = 16)                                       (3mks)

20.       Aluminium is extracted from its ore by the process of electrolysis .                          (1mk)

(i)         Name the ore of aluminium that is normally used.

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

(ii)        Aluminium ore in (i) above has very high melting point (2015°C) though it is electrolysed at a lower temperature of  a bout 900°C. Explain how the low temperature is achieved.

( 1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

(iii)       In the above process graphite electrodes are used. What is the disadvantage of using this kind of electrode?                                                                                                        (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

21.       A wooden splint glowing on both ends was fixed as shown in the diagram. The experiment was carried out as indicated.

2010 KCSE Chemistry Trial P1-001

a)         What will be observed on the glowing splint ends A and B if heating is done at the same time?                                                                                                                             (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

b)         Explain the observation in (a) above.                                                                          (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

c)         One of the products in this experiment is useful to rocket scientist is useful to rocket scientists when going into space.

State two ways in which the scientists use this product.                                            (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

22.       30cm3 of Hydrogen gas diffuses through a porous plug in 2 minutes. How long will 90cm3

of hydrocarbon gas of molecular mass 72 taken to diffuse through the same plug under same

conditions. (H = 1  , C = 12)                                                                                                   (3mks)

23.       The diagram below represents a charcoal burner. Study it and answer at the question that follow.

2010 KCSE Chemistry Trial P1-001

a)         Explain what takes place in region (III)                                                                     (2mks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

b)         Write tan equation for the reaction taking place in region II.                                     (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

24.       When aqueous mixture containing 60g of potassium bromide and 7g of potassium sulphate in 100g of water at 80°C was cooled to 0°C some crystals were formed.

(i)         Name the method used to obtain the crystals.                                                                        (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

(ii)        Suggest ore industrial application of the method named in (i) above.                       (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………………………

25.       Give two reasons why ammonium nitrate is such a good fertilizer.                                       (2mks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

26.       The table below gives information of four elements by letters A,B, C and D. Study it and answer the questions that follow. The letters do not represent the actual symbol of the elements.

Element Electron arrangement Atomic radius (nm) Ionic radius nm
A 2.8.2 0.136 0.065
B 2.8.7 0.097 0.181
C 2.8.8.1 0.203 0.133
D 2.8.8.1 0.174 0.097

a)         Which two elements have similar properties? Explain                                                (2mks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

b)         Why is the ionic radius any element B greater than its atomic radius.                       (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

27.       In an experiment soap solution was added to three samples of water. The table below shows the volume of soap solution required to form lather with 500cm3 of water before and after boiling.

Sample A Sample B Sample C
Volume of soap before water is boiled 12.4 4.0 29.0
Volume of water after water is boiled 4.0 4.0 29.0

a)         Which sample is likely to be

(i)         temporary hard water.                                                                                                 (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

(ii)        permanent hard water.                                                                                                            (1 mk)

………………………………………………………………………………………………………………………………………………………………………………………………

b)         Write the formula of a compound that could be present in sample A but not in sample  C.

(1mk)

28.       Starting with zinc oxide, describe how you can prepare a sample of lead ( II) sulphate.      (2mks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

29.       Chlorine can be prepared using the following reagents potassium manganate (VII) and concentrated hydrochloric acid.

a)         State the role of potassium manganate (VII) in the reaction.                                     ( ½ mk)

………………………………………………………………………………………………………………………………………………………………………………………………

b)         Name the bleaching agent formed when chlorine gas is passed through cold dilute sodium hydroxide solution.                                                                                                          ( ½ mk)

………………………………………………………………………………………………………………………………………………………………………………………………

c)         Write an equation showing the bleaching action of the bleaching agent named in b) above

on the dye                                                                                                                   (1mk)

………………………………………………………………………………………………………………………………………………………………………………………………

30.       Given phosphorus has atomic number of 15. Write the electron arrangement of phosphorous in PO43-.                                                                                                                                           (2mks)

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

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