Chem

KIKAAYA COLLEGE SCHOOL END OF TERM 1 EXAMS S.3 CHEMISTRY TIME: 2 hours SECTION A: 1. Which of the following oxides has the most lonic structure? A) p2 o5 (B) sl o2 (c) Al2 o3 (d) Na2 o 2. Which of the following process is not used to remove hardness in water? A) Treatment with sodium carbonate B) Addition of calcium hydroxide C) Distillation of water D) Addition of sodium stearute 3. Which of the following salts is less soluble in water? A) Ca cl2 B)Ca co3 D) Ca(No3)2 D) Ca So4 4. The rate of reaction between zinc and hydrochloric ac id can be increased by. A) Diluting the hydro chloric acid B) Using powder instead of zinc granules C) Adding H+ as a catalyst. D) Placing the reaction vessel in an ice bath. 5. When ammonium nitrate is heated it produces . A) Nitrogen dioxide B) Ammonia C) Dinitrogen monoxide D) Nitrogen monoxide 6. Which one of the following ions can be contismed by brown ring test. A) Cl – B) No3C) Co23D) So427. Which of the following is not an acidic oxide A) Carbon dioxide B) Carbonmonoxide C) Sulphur dioxide D) Phosphorus (v) oxide 8. Which of the following salts can be prepared by precipitation ? A) Sodium chloride B) Lead (II) chloride C) Potassium chloride D) Copper (II) chloride

9. To the ashes obtained from the combustion of magnesium in air, water was added and the mixture warmed,the product is. A) Mg o B) NH3 C) Mg3 N2 D) Mg (H)2 10. Which of the following oxides is not amphoteric? A) Zn o B) Al2 O3 C) Fe2 O3

D) Pbo20

11. An atom of an element has the structure 10x . The element A) Forms covalent bond readly with non- metals B) Forms ionic bond with non-metals C) Belong to group to the periodic table D) Has tell shell of electrons 12. Which one of the following is the least effective substance for putting off a petrol fire. A) Water B) Carbondioxide C) Powder D) Valatile liquid 13. Which of the following is a mixture A) Diamond B) Brass 14. An acid x2 so4 lonises as x2 so4 the acid is A) 1 B) 2 C) -3

C) Aluminium

D) Gold

2H+ + So42- the baseity of D) 4

15. Which of one of the following substance is an example of an allotrope? A) Copper B) Bronze C) Carbon D) Carbonate 16. Which one of the metal a toms whose electronic structure given bellow forms a nitrate of the type m(No3)2 A) 2:8:0 B) 2:8:1 C) 2:8:2 D) 2:8:3. 17. Which of one of the following metals reacts with water ordinary temperature to give hydrogen? A) Aluminium B) Calcium C) Zinc D) Iron 18. An example of a gas which was as oxidizing agent is A) Lead B) Silver C) Copper D) Magnesium 19. A white sold formed when lime water is left exposed to air for some time is A) Calcium carbonate B) Calcium oxide C) Calcium hydroxide D) Calcium chloride 20. Sodium burns in limited air forming A) Sodium oxide B) Sodium peroxide C) Sodium hydroxide D) Sodium hydride 21. The catalyst used in the manufacture of nitric acid is

A) Iron

B) Platinum

C) Iron (iii) oxide

D) Vanadium (v) oxide

22. When sodium was heated of changed to gas without passing through the liquid state. This change of state is called A) Evaporisation B) Sublimation C) Distulation D) Condensation 23. Air contain mainly. A) Carbondioxide D) Water vapour

B) Oxygen

C) Nitrogen

24. An acid accidentally spilled on a pupils cloth is best neutralized solution of PH. A) 1 B) 4 C) 5 D) 8 25. In which group of the periodic table is the element 2412m found? A) (I) B) (II) C) (III) D) (IV) 26. The product formed when candle burns in excess air is A) Carbon monoxide B) Methane C) Water vapour

D) Soot

27. Which of the following salt is used in water purification A) Ammonium nitrate B) Magnesium carbonate C) Iron (III) sulphate D) Potassium chloride 28. Which one of the following statement about graphite is tales? A) It has a layer structure B) It retract light rays strongly C) It is an excellent lubricant in oil D) It has a high density 29. When of the following metals react with Nitrogen when heated A) Lead

B) Silver

C) Copper

D) Magnesium

30. In each of the questions 30 to 40 one or more of the answers given may be correct. Read each question carefully and then indicate the correct answer according to the following A) If 1,2,3 only are correct B) If 1,3 only are correct C) If 2,4 only are correct D) If 4 only is correct 31. When potassium chlorate is heated with manganese (IV) oxide, it decomposes to give. A) Oxygen B) Chlorine C) Potassium chloride D) Manganese chloride 32. Nitric acid shows the following property or properties. 1)Turn litmus blue 2) Forms salts with bases 3) Is powerful reducing agent 4) Produce carbon dioxide with carbonates 33. A calcium ion possesses 1) 20 protons 20 neutrons 4) 40 electrons

2) 22 electrons

3)

34. Which of the following substance(s) is /are formed when copper (III) nitrate is heated strongly 1) Copper (II) oxide 2) Nitrogen dioxide 3) Oxygen 4) Copper metal 35. Iron is prevented from rusting by 1) Greasing 2) Electroplating 3) Galvanising 4) Neutralisingn Each of the questions 36 to 40 consist of an assertion (statement) on the left hand side and a reason on the right hand side. A) If both the assertion and the reason are true statements and the reasons is a correct explainaion of the assertion B) If both the assertion and the reason is not a correct explanation of the assertion C) If the assertion is true but the reason is not a correct statement. D) If the assertion is not correct but the reason is a true statement Assertion A True B True C True D Incorrect 36. Magnesium has oxidation Number of +2

Instruction summarized. Reason True (reason is a correct explanation True (reason is not a correct explanation incorrect True magnesium lack size Because electrons to complete the act of structure

36. Copper react with concentrated Nitric acid to produce nitrogen because 37.

monoxide Permanent hardness of water is caused by presence Because

Copper is above hydrogen in the Electro chemical series These elements form sulphate compounds

of magnesium and calcium ions in water 37. Oxygen molecucle is

Because

it has high melting point

38. Ammonia gas turns moist

Because

it is a volatile gas

SECTION B 41 (a) Define the terms

(i) a normal salt (b) Give one example of (i) a normal salt (ii) a acidic salt 42. Magnesium reacts with steam to give a solid x and a gas y (a) Identify (i) Solid x (ii) a gas y (b) State how y could be tested.

© Write equation for the reaction between x and hydrochloric acid 43. The atomic numbers of carbon and chlorine are 6 and 17 respectively. (a) Draw the diagram to show the electronic structure of (i) Carbon (ii)

Chlorine

(b) Write the structural formula of the compound that can be formed between carbon and chlorine. (c) Would you expect the compound in (b) to conduct electricity? Give a reason for answer. 45. State the approximate percentage of oxygen in the atmosphere. (b) Name the process by which oxygen is (i) Used up from the atmosphere. (iii)

Replaced in the atmosphere.

(d) State what would be observed if a pieces of burning phosphorus is lowered into a far of oxygen. END