Chemistry WAEC past questions and answers

Chemistry WAEC past questions and answers

Here are 20 chemistry WAEC exam questions with options and answers:

What is the atomic number of carbon?

a) 6

b) 12

c) 14

d) 8

Answer: a) 6

Which element is a noble gas?

a) Oxygen

b) Neon

c) Sodium

d) Hydrogen

Answer: b) Neon

What is the chemical symbol for gold?

a) Au

b) Ag

c) Fe

d) Hg

Answer: a) Au

Which of the following is a halogen?

a) Chlorine

b) Calcium

c) Iron

d) Potassium

Answer: a) Chlorine

How many electrons are in a neutral oxygen atom?

a) 6

b) 7

c) 8

d) 9

Answer: c) 8

What is the formula for water?

a) H2O

b) CO2

c) CH4

d) O2

Answer: a) H2O

Which gas is responsible for the Earth's ozone layer depletion?

a) Oxygen

b) Carbon dioxide

c) Chlorofluorocarbons (CFCs)

d) Nitrogen

Answer: c) Chlorofluorocarbons (CFCs)

What is the pH of a neutral solution?

a) 0

b) 7

c) 14

d) 1

Answer: b) 7

Which type of bond is formed between two nonmetals sharing electrons?

a) Ionic bond

b) Covalent bond

c) Metallic bond

d) Hydrogen bond

Answer: b) Covalent bond

What is the chemical formula for methane?

a) CH4

b) CO2

c) H2O

d) NH3

Answer: a) CH4

Which gas is responsible for the greenhouse effect?

a) Oxygen

b) Carbon dioxide

c) Nitrogen

d) Argon

Answer: b) Carbon dioxide

What is the chemical formula for sulfuric acid?

a) H2SO4

b) NaCl

c) HCl

d) HNO3

Answer: a) H2SO4

What is the chemical formula for table salt?

a) NaCl

b) H2O

c) CO2

d) CaO

Answer: a) NaCl

Which element is essential for combustion to occur?

a) Carbon

b) Oxygen

c) Hydrogen

d) Nitrogen

Answer: b) Oxygen

Which subatomic particle has a positive charge?

a) Electron

b) Proton

c) Neutron

d) Positron

Answer: b) Proton

What is the molar mass of water (H2O)?

a) 18 g/mol

b) 32 g/mol

c) 2 g/mol

d) 10 g/mol

Answer: a) 18 g/mol

Which gas is produced during photosynthesis?

a) Oxygen

b) Carbon dioxide

c) Hydrogen

d) Nitrogen

Answer: a) Oxygen

What is the chemical formula for ammonia?

a) NH3

b) CH4

c) CO2

d) O2

Answer: a) NH3

Which law states that the total pressure of a gas mixture is the sum of the partial pressures of its components?

a) Avogadro's Law

b) Boyle's Law

c) Charles's Law

d) Dalton's Law

Answer: d) Dalton's Law

What is the name of the process where a solid changes directly into a gas without passing through the liquid phase?

a) Sublimation

b) Evaporation

c) Condensation

d) Fusion

Answer: a) Sublimation