Chemistry 2019 Past Questions | WAEC
- The periodic table is an arrangement of elements according to their?
- A. Oxidation number
- B. Atomic number
- C. Mass number
- D. Number of neutrons
2. A solid with higher melting and boiling points is likely to be?
- A. Covalent compound
- B. A Dative compound
- C. An Electrovalent compound
- D. A Non-metal
3. Which of the following metals reacts slowly with cold water?
- A. Iron
- B. Silver
- C. Calcium
- D. Potassium
4. which of the following elements has the highest ionization energy?
- A. Calcium
- B. Chlorine
- C. Flourine
- D. Magnesium
5. The bleaching action of chlorine is through the process?
- A. Hydration
- B. Hydrolysis
- C. Reduction
- D. Oxidation
6. The bleaching action of chlorine is due to its ability to react with water to form oxochlorate(i)acid
If 6.5g of magnesium ribbon reacts completely with Hydrochloric acid, how many grams of hydrogen gas would be liberated?
Mg(s) + 2 HCl(aq) –> MgCl 2(aq) + H 2(g)
[ H = 1.0, Mg = 24.0 ]
- A. 0.54g
- B. 0.70g
- C. 1.08g
- D. 1.40g
7. Calcium and magnesium belong to the group of the periodic table because both?
- A. are metals
- B. form cations
- C. form colourless salts
- D. have same number of valence electrons
8. Which of the substances is non-polar?
- A. Bromine
- B. Ammonia
- C. Water
- D. Hydrogen Bromide
9. Which of the following pairs of components have the same molecular mass?
[ H = 1.0, C = 12.0, O = 16.0 ]
- A. Ethene and Ethyne
- B. Ethane and Ethene
- C. Carbon (ii) Oxide and Ethene
- D. Carbon (iv) Oxide and Ethyne
10. When an equilibrium is established between dissolved and undissolved solutes, the solution is said to be?
- A. Saturated
- B. Unsaturated
- C. Concentrated
- D. Diluted
11. How many moles of carbon(iv)oxide contains 16.0g of oxygen?
[ C = 12.0, O = 16.0 ]
- A. 0.20 mol
- B. 0.25 mol
- C. 0.40 mol
- D. 0.50 mol
12. Stoichiometry is based on the law?
- A. multiple proportion
- B. constant composition
- C. conservation of energy
- D. conservation of mass
13. What is the percentage by mass of H in CH3COOH
- A. 1.7%
- B. 5.0%
- C. 6.7%
- D. 7.1%
14. Which of the following compounds has coordinate bonds in its structure?
- A. Al2Cl6
- B. MgCl2
- C. AgCl
- D. NaCl
15. The name of the compound CH3C(CH3)CH2CH2CH3
- A. 2 – methyl butane
- B. 2,2 – dimethyl butane
- C. 2 – methyl pentane
- D. 2,2 – dimethyl pentane
