iGCSE Chemistry Multiple Choice (Extended) : 4.2 Hydrogen–oxygen fuel cells: Exam Style Questions Paper 2

Question

Which statement describes an advantage of using a hydrogen-oxygen fuel cell in a car compared to a gasoline engine?

A) The hydrogen is difficult to store.
B) The hydrogen is highly flammable.
C) The hydrogen used is made from hydrocarbons.
D) The only chemical product is water.

▶️ Answer/Explanation

Solution

Ans: D

The main advantage of hydrogen-oxygen fuel cells is their clean operation, producing only water as a byproduct (H₂ + ½O₂ → H₂O). This makes them environmentally friendly compared to gasoline engines that produce CO₂ and other pollutants.

Options A and B describe disadvantages, not advantages. Option C is incorrect because while hydrogen can be made from hydrocarbons, it can also be produced through electrolysis of water using renewable energy.

Question

Which statement about a hydrogen-oxygen fuel cell is not correct?

A) Chemical energy is converted into electrical energy.
B) Hydrogen is oxidised.
C) The reaction that takes place is endothermic.
D) Water is the only chemical product.

▶️ Answer/Explanation

Solution

Ans: C

In a hydrogen-oxygen fuel cell:

1. Chemical energy is indeed converted to electrical energy (A is correct).

2. Hydrogen is oxidized at the anode: H₂ → 2H⁺ + 2e⁻ (B is correct).

3. The overall reaction is exothermic, not endothermic (C is incorrect, which makes it the correct answer).

4. The only product is water: 2H₂ + O₂ → 2H₂O (D is correct).

The reaction in a fuel cell is exothermic because it releases energy (heat and electricity). The question asks for the statement that is NOT correct, which is C.

Question

Hydrogen fuel cells can be used to power cars.
Which statements about a fuel cell are correct?
1 The balanced equation for the reaction is H₂ + O₂ = H₂O.
2 The fuel cell generates electricity.
3 In the fuel cell hydrogen is reduced.
4 The reactants are gases at room temperature.
A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

Answer/Explanation

Ans: C

Question

Which equation represents a reaction that takes place in a fuel cell?
A \(C + O_2 \rightarrow CO_2\)
B \(2H_2 + O_2 \rightarrow 2H_2O\)
C \(CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O\)
D \(C_3H_8 + 5O_2 \rightarrow 3CO_2 + 4H_2O\)

Answer/Explanation

Ans: B

iGCSE Chemistry Multiple Choice (Extended) : 4.2 Hydrogen–oxygen fuel cells: Exam Style Questions Paper 2

Question

Question

Resources

Members

Company