Chemistry 2020 Past Questions | WAEC
16. A factor that is considered most important when siting a chemical industry is?
- A. nearness to other industrial establishments
- B. nearness to raw materials
- C. favourable climate conditions
- D. availability of storage facilities
17. The boiling point of pentane is higher than that of propane because?
- A. carbon-carbon single bonds are stronger than carbon-hydrogen bonds.
- B. Pentane has more covalent bonds to break
- C. Pentane does not burn easily as propane
- D. The intermolecular forces in pentane are stronger than those of propane
18. Which of the following solids would not decompose on heating?
- A. Ammonium chloride
- B. Lead (i) trioxonitrate (V)
- C. Potassium trioxocarbonate (IV)
- D. Sodium hydrogen trioxocarbonate (IV)
19. The following molecules have double covalent bonds between two atoms except?
- A. oxygen
- B. carbon (IV)oxide
- C. ethene
- D. water
20. The type of isomerism exhibited by cis and trans isomers is?
- A. positional
- B. geometrical
- C. functional
- D. optical
21. Which of the following compounds has the lowest boiling point?
- A. C4H10
- B. CH3COOH
- C. H2O
- D. C2H5OH
22. An alkanol containing 60% carbon by mass would have a molecular formula [H=1.0. C-12.0, O= 16.0]
- A. CH3OH
- B. C2H5OH
- C. C3H7OH
- D. C4H9OH
23. Which of the following compounds would release hydrogen when reacted with sodium metal?
- A. I only
- B. I and II only
- C. Il and IIl only
D. I and Ill only
24. Which of the following substances is not a reducing agent?
- A. C
- B. CO
- C. O2
- D. H2
25. Which of the following statements is correct for a reaction at equilibrium?
- A. All reactions cease to occur
- B. The reaction has gone to completion
- C. The rates of the forward and backward reactions are equal
- D. The amount of product equals the amount of reactants
26. Which of the following reactions are always exothermic? 1. Neutralization Il. Decomposition III. Combustion
- A. I and II only
- B. I and III only
- C. II and IIl only
- D. I, II and III
27. Which of the following standard conditions is not correct about energy changes?
- A. Standard temperature is 298K
- B. B. Standard pressure is 1 atm
- C. Concentration of solution must be 1 mol/dm33
- D. ΔH at 298 K is the activation energy
28. f 5.0 cm−3of 0.200 mol dm-3Na2CO3 was diluted to 250cm-3 solution, what would be the concentration of the resulting solution?
- A. 0.004 mol dm-3
- B. 0.020 mol dm-3
- C. 0.200 mol dm-3
- D. 0.400 mol dm-3
29. The initial volume and pressure of a given mass of gas is V and 3.P. What is its pressure if its volume is increased to 2V at constant temperature?
- A. 3 P
- B. 2P
- C. 3/2P
- D. 2/3 P
30. What volume of oxygen at s.t.p is required to burn completely 7.5 dm33of methane according to the following equation?
CH4 g + 202 g → CO2 g + H2Og
- A. 3.75 dm3
- B. 7.59 dm3
- C. 15.0 dm3
- D. 30.0dm3