Get premium membership and access revision papers, questions with answers as well as video lessons.
Chemistry Question Paper
Chemistry
Course:Secondary Level
Institution: Kcpe question papers
Exam Year:
Name the process that takes place when
(i) Fat or oils are hydrolyzed using an alkali. (1 mk).
(ii) Sulphur is heated with natural rubber. (1 mk)
2. When anhydrous Calcium Chloride is exposed to the atmosphere. It forms a solution.
(a) Name the process that takes place. (1 mk)
(b) State one use of the process named in 2 (a) above. (1 mk)
3. Study the energy level diagram for the reaction shown below and use it to answer the questions that follow.
(i) State and explain two ways of increasing the yield of SO3 per unit time from the diagram.
(2 mks)
(ii) What do the following represent?
……………………………………………………………………………. ( ½ mk)
……………………………………………………………………………. ( ½ mk)
4. The diagram below shows an incomplete set-up of preparation and collect of dry hydrogen chloride gas. Use it to answer the questions that follow.
(a) Identify solid M and liquid P.
M
P
(b) Complete the diagram above to show how the preparation and collection was achieved.
(1 mk)
5. Give the reaction type of the following:
(i) Reaction between Butan – 1-oic acid and Pentan – 1- ol in the presence of drops of conc. Sulphuric acid to form an organic compound. (1 mk)
(ii) Reaction between Chlorine and Potassium Iodide to form a dark brown solution. (1 mk)
(iii) Reaction between bromine and methane in the presence of U.V light (1 mk)
6. A fossil was discovered in the year 2007. Its half-life was found to be 440 yrs. Calculate the time
it will take for the mass of the fossil to have reduced from 240g to 15g. (3 mks)
7. A form four student accidentally mixed Sodium Carbonate and Calcium Carbonate. Describe how he would obtain a dry sample of Sodium Carbonate from the mixture. (3 mks)
8. State the conditions under which ammonia gives the following products when heated
(i) Nitrogen and hydrogen. (1 mk)
(ii) Nitrogen and water. (1 mk)
(iii) Nitrogen (II) oxide and water. (1 mk)
9. (a) The atomic number of Sulphur hydrogen and oxygen are 16, 1 and 8 respectively. Write
the electron arrangement of Sulphur in the following substances.
(i) H2S……………………………………………………………………. (1 mk)
(ii) SO32-………………………………………………………………….. (1 mk)
(b) State the number of neutrons and electrons in the species of Aluminum shown below:
Neutrons …………………………………………………………….. ( ½ mk)
Electrons ……………………………………………………………. ( ½ mk)
10. The graph below shows the behaviour of a fixed mass of a gas at constant temperature.
(i) What is the relationship between the volume and the pressure of the gas. (1 mk)
(ii) 12 litres of oxygen gas at one atmosphere pressure were compressed to 2.5 atmospheres
pressure at constant temperature. Calculate the volume occupied by the oxygen gas.
(2 mks)
11. 20 cm3 of 2 M Sulphuric (IV) acid reacted completely with 3.2 g of WOH (O=16, H=1) Calculate the R.A.M of W in the formula WOH. (3 mks)
12. Study the diagram below and answer the questions that follow.
(a) Identify the solvent used in step I and step II.
I…………………………………………………………………………………….. ( ½ mk)
II …………………………………………………………………………………… ( ½ mk)
(b) State and explain what is observed if a red litmus paper was dipped in solution B and C. (2 mks)
13. The figure below shows part of non-luminous flame.
(a) (i) Describe an experiment that would confirm that region labeled A is not suitable for
heating. (1 ½ mks)
(ii) Explain why luminous flame produce light and soot. (1 ½ mks).
14. An organic compound with the formula C4H10O reacts with sodium metal to give hydrogen gas and a white solid.
(a) Give the formula of the white solid. (1 mk)
(b) To which homologous series does the white solid belong? (1 mk)
(c) Write the equation for the reaction between the organic compound C4H10O and sodium metal. (1 mk)
15. (a) Carbon (IV) oxide is bubbled through Calcium hydroxide until there is no further change. Explain using equations the changes observed. (2 mks)
(b) Explain why diamond is used in cutting of glass and drilling. (1 mk)
16. The table below shows ammeter reading recorded when 2M Sulphuric (IV) acid and 2M ethanoic acid were tested separately.
Electrolyte Current (A)
2M Sulphuric acid 8.1
2M Ethanoic acid 2.5
Explain the difference in the ammeter readings. (2 mks)
17. The figure below shows cross – sections of two pieces of iron coated with Zinc and Copper respectively.
Which piece of iron would rust when the holes were filled with water and left for sometime? Explain. (2 mks)
18. (i) Define a dynamic equilibrium. (1 mk)
(ii) The equation below shows a reaction at equilibrium
2CrO42-(aq) + 2H+ (aq) Cr2O72-(aq) + H2O (l)
If a graph of reaction rate against time plotted, the curve obtained is as below.
Giving a reason, identify species A and B.
A (1 mk)
B (1 mk)
19. (a) Using electrons in the outermost energy level, draw a dot (.) and cross (X) diagram for the ion of PH4+ and compound B2O3. (P=15, H=1, B=5, O= 16)
(i) PH4+ (1 mk)
(ii) B2O3 (1 mk)
(b) The formula of the compound formed when Aluminum and chlorine react is Al2Cl6. Name the types of bonds that exist in the compound. (1 mk)
20. Sulphur (IV) oxide gas was bubbled through acidified potassium chromate (VI) solution and Iron (III) Sulphate solution chromate. Explain the observations made in each case.
(i) With Potassium Chromate (VI) solution. (1 ½ mk2)
(ii) Iron (III) Sulphate solution (1 ½ mks)
21. A liquid X is added dropwise to 20cm3 of Urea fertilizer (NH2)2 CO solution. The PH value is noted after the addition of every 10 drops and a graph of PH against number of drops is drawn as shown below.
(a) From the evidence on the graph, state the nature of liquid X added and explain your deduction (2 mks)
(b) The table below shows solution and their PH value.
Solution PH value
P
R
R 2.0
7.0
14.0
Select two solutions that would react with zinc hydroxide. Explain. (1 mk)
22. State and explain what is observed when a burning piece of magnesium is lowered into a gas jar containing dry chlorine gas. (2 mks)
23. The set-up below was used during the electrolysis of Magnesium Sulphate solution using graphite electrons.
(i) Identify the anode and the cathode. (1 mk)
Anode: …………………………………………………………………………….
Cathode: …………………………………………………………………………..
(ii) Write half ionic equation at the anode and cathode: (1 mk)
Anode: ……………………………………………………………………………
(iii) Explain the PH change of the electrolyte during the experiment. (1 mk)
24. Calculate the standard enthalpy of formation of carbon disulphide given that:-
S(s) + O2 (g) SO2
CS2 (l) + 3O2 (g) CO2 + 2SO2
C(s) + O2 (g) CO2 (g)
25 (2 mks)
More Question Papers