JAMB and WAEC Chemistry questions: Energy changes

38 questions with answers and explanations. Tap an option to check yourself.

All topics Acids, bases and salts · 58 Air · 37 Atomic structure and bonding · 59 Chemical combination · 58 Chemical equilibrium · 37 Chemistry and industry · 35 Electrolysis · 41 Energy changes · 38 Environmental pollution · 32 Kinetic theory of matter and gas laws · 45 Metals and their compounds · 47 Non-metals and their compounds · 45 Organic compounds · 72 Oxidation and reduction · 41 Rates of chemical reaction · 38 Separation of mixtures and purification · 42 Solubility · 36 Water · 39

Question 21· Energy changes· JAMB
Entropy is a measure of
Explanation and discussion
Question 22· Energy changes· WAEC
Burning butane in a gas cooker is described as exothermic because
Explanation and discussion
Question 23· Energy changes· JAMB
A reaction with a negative ΔH is
Explanation and discussion
Question 24· Energy changes· WAEC
Heat released when 2 mol of a substance burns is 1,600 kJ. Find the heat of combustion per mole.
Explanation and discussion
Question 25· Energy changes· JAMB
In an exothermic reaction, the products have
Explanation and discussion
Question 26· Energy changes· WAEC
An energy profile diagram where the products are higher in energy than the reactants represents
Explanation and discussion
Question 27· Energy changes· WAEC
A reaction that gives out heat to the surroundings is
Explanation and discussion
Question 28· Energy changes· WAEC
Activation energy is the
Explanation and discussion
Question 29· Energy changes· JAMB
In a reaction, 1000 kJ is absorbed in breaking bonds and 1200 kJ is released in forming bonds. Find ΔH.
Explanation and discussion
Question 30· Energy changes· JAMB
The standard enthalpy of formation of an element in its standard state is
Explanation and discussion
Question 31· Energy changes· JAMB
For 2H₂(g) + O₂(g) → 2H₂O(l), ΔH = −572 kJ. How much heat is released when 1 g of hydrogen burns? (H = 1)
Explanation and discussion
Question 32· Energy changes· JAMB
The minimum energy that colliding particles must have before they react is the
Explanation and discussion
Question 33· Energy changes· WAEC
Which of these processes is endothermic?
Explanation and discussion
Question 34· Energy changes· JAMB
The energy profile shown represents a reaction that is
Explanation and discussion
Question 35· Energy changes· WAEC
The heat change when one mole of water is formed from the neutralisation of an acid by a base is the heat of
Explanation and discussion
Question 36· Energy changes· JAMB
The combustion of 1 mol of methane releases 890 kJ. How much heat is released when 4 g of methane burns? (C = 12, H = 1)
Explanation and discussion
Question 37· Energy changes· WAEC
For C + O₂ → CO₂, ΔH = −394 kJ/mol. How much heat is released when 6 g of carbon burns completely? [C = 12]
Explanation and discussion
Question 38· Energy changes· JAMB
An exothermic reaction is one in which:
Explanation and discussion

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JAMB and WAEC Chemistry questions: Energy changes

Entropy is a measure of

Burning butane in a gas cooker is described as exothermic because

A reaction with a negative ΔH is

Heat released when 2 mol of a substance burns is 1,600 kJ. Find the heat of combustion per mole.

In an exothermic reaction, the products have

An energy profile diagram where the products are higher in energy than the reactants represents

A reaction that gives out heat to the surroundings is

Activation energy is the

In a reaction, 1000 kJ is absorbed in breaking bonds and 1200 kJ is released in forming bonds. Find ΔH.

The standard enthalpy of formation of an element in its standard state is

For 2H₂(g) + O₂(g) → 2H₂O(l), ΔH = −572 kJ. How much heat is released when 1 g of hydrogen burns? (H = 1)

The minimum energy that colliding particles must have before they react is the

Which of these processes is endothermic?

The energy profile shown represents a reaction that is

The heat change when one mole of water is formed from the neutralisation of an acid by a base is the heat of

The combustion of 1 mol of methane releases 890 kJ. How much heat is released when 4 g of methane burns? (C = 12, H = 1)

For C + O₂ → CO₂, ΔH = −394 kJ/mol. How much heat is released when 6 g of carbon burns completely? [C = 12]

An exothermic reaction is one in which: