Chemistry Waec Past Questions And Answers (Objective and Theory)

Here are 20 WAEC Chemistry questions, including a theory section with 5 questions. Options and answers are provided for each multiple-choice question.

 

Multiple Choice Section:

What is the chemical symbol for gold?

 

A) Au

B) Ag

C) Fe

D) Cu

Answer: A

Which of the following is a noble gas?

 

A) Oxygen

B) Helium

C) Nitrogen

D) Hydrogen

Answer: B

In a neutral atom, the number of electrons is equal to:

 

A) Atomic number

B) Mass number

C) Proton number

D) Neutron number

Answer: A

What is the chemical formula for sulfuric acid?

 

A) H2SO3

B) H2SO4

C) H2S

D) SO2

Answer: B

Which process involves the conversion of a solid directly into a gas?

 

A) Sublimation

B) Condensation

C) Vaporization

D) Fusion

Answer: A

The pH of a solution with a hydrogen ion concentration of 1 x 10^-8 M is:

 

A) 8

B) 6

C) 4

D) 2

Answer: A

What is the function of catalysts in chemical reactions?

 

A) Increase temperature

B) Increase pressure

C) Speed up the reaction

D) Slow down the reaction

Answer: C

Which of the following is a halogen?

 

A) Sodium

B) Chlorine

C) Calcium

D) Potassium

Answer: B

The process of rusting is an example of:

 

A) Combustion

B) Oxidation

C) Reduction

D) Sublimation

Answer: B

What is the chemical name for baking soda?

 

A) Sodium chloride

B) Sodium carbonate

C) Sodium bicarbonate

D) Sodium hydroxide

Answer: C

Theory Section:

Explain the concept of electronegativity and its significance in chemical bonding.

 

Describe the differences between exothermic and endothermic reactions, providing examples of each.

 

Discuss the principles behind Avogadro’s Law and its application in calculating molar volumes of gases.

 

Explain the process of polymerization and provide examples of synthetic polymers used in everyday life.

 

Elaborate on the factors affecting reaction rates and how catalysts influence reaction kinetics