Chemistry JAMB, WAEC, NECO AND NABTEB Official Past Questions

22

What volume of hydrogen will be produced if 100cm3 of ammonia is completely decomposed at constant temperature and pressure? The equation for the reaction is 2NH3(g) → N2(g) + 3H2(g)

  • A. 50cm3
  • B. 150cm3
  • C. 200cm3
  • D. 300cm3
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23

Which of the following decreases when a given mass of gas is compressed to half its initial volume?

  • A. Average intermolecular distance
  • B. Frequency of collisions
  • C. Number of molecules present
  • D. Atomic radius of each particle
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24

If a metal R forms a compound with the formula R(NO3)2 the formula of its tetraoxosulphate (VI) is

  • A. R(SO4)2
  • B. RSO4
  • C. R2SO4
  • D. R2(SO4)3
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25

The conclusion from Rutherford’s radioactive substance alpha-scattering experiment is that

  • A. atoms are mostly empty space with a samll
  • B. emissions from radioactive substances consist of three main components
  • C. there is unclear pull on orbital electrons
  • D. electrons are deflected by both magnetic and electric fields
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26

Waste plastics accumulate in the soil and pollute the environment because plastic materials are

  • A. insoluble in water
  • B. non-biodegradable
  • C. easily affected by heat
  • D. inflammable
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27

Acidic industrial waste can be treated with

  • A. lime
  • B. brine
  • C. water
  • D. ethanol
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28

Which of the following reactions represents the change that occurs when a photographic film is exposed to sunlight?

  • A. Ag → Ag+ + e-
  • B. Ag+ + e- → Ag
  • C. 2Ag + Br22 → AgBr
  • D. Ag+ + Br- → AgBr
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29

If 10 cm 3 of distilled water is added to 10 cm3 of an aqueous salt solution, the concentration of the solution

  • A. increases
  • B. decreases
  • C. remains constant
  • D. doubles
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30

Sugars can be hydrolyzed at room temperature by the action of

  • A. mineral acids
  • B. strong bases
  • C. enzymes
  • D. oxidants
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31

Which of the following constitutes an advantage in the use of hard water?

  • A. Formation of scum with soap
  • B. Furring of kettles
  • C. Blockage of water pipes
  • D. Formation of strong bones
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32

What is the function of H2SO4 in the following reaction?

C12H22O11 conc. H2SO4 → 12C + 11H2O

  • A. Oxidizing agent
  • B. Strong acid
  • C. Dehydrating agent
  • D. Catalyst
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33

Which of the following polymers contains nitrogen?

  • A. Nylon
  • B. Polyvinyl chloride
  • C. Polyethene
  • D. Cellulose
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34

One of the products of combustion of pentane in excess air is

  • A. pentanol
  • B. pentene
  • C. nitrogen (ll) oxide
  • D. carbon (IV) oxide
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35

Benzene produces more soot than ethene on burning because benzene

  • A. has a higher molar mass
  • B. has a higher degree of unsaturation
  • C. undergoes substitution and addition reactions
  • D. is a liquid at room temperature
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36

Hydrogenation of butene yields

  • A. butyne
  • B. butane
  • C. pentence
  • D. butanol
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37

A feasible cell was constructed by joining the two half cells below. Cu2+ (aq) + 2e- → Cu(s) Eo = +0.34 V; Zn\({^2+}\) + 2e\(^-\) → Zn\((_s)\) Eo = – 0.76V. What is the standard e.m.f. of the cell?

  • A. - 1.1V
  • B. - 0.42V
  • C. +0.42V
  • D. +1.1V
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38

In the electrolysis of CuSO4(aq) using copper electrodes, the reaction at the anode is

  • A. discharge of SO4 2-
  • B. discharge of OH-
  • C. dissolution of copper electrode
  • D. evolution of oxygen
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39

Given that the order of reactivity of four metals is P>Q>R>S, which of the following reactions is feasible?

  • A. S + P+ → P + S +
  • B. Q + S+ → S + Q+
  • C. R + P+ → P + R+
  • D. S + Q+ → Q + S+
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40

A concentrated solution containing H+, Cu2+,OH- and CI- was electrolyzed using platinum electrodes which of the ions will be discharged at the cathode?

  • A. H+
  • B. Cu2+
  • C. OH-
  • D. CI-
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41

Which of the following substances decomposes when an electric current is passed through it?

  • A. Glucose solution
  • B. Zinc rod
  • C. Hydrochloric acid
  • D. Tetrachloromethane
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42

What is oxidized in the reaction represented by the following equation? 3CU + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O

  • A. Oxygen
  • B. Hydrogen
  • C. Nitrogen
  • D. Copper
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