C7

Question 1

When making ionic equations, you can disregard…

Answer 1

spectator ions which do not change

Question 2

The greater the reactivity between 2 metals used in a battery….

Answer 2

the higher the voltage produced

Question 3

What happens when 2 metals are joined by a wire and dipped in a salt solution?

Answer 3

The more reactive metal will donate electrons to the less reactive metal. This forms a simple cell.

Question 4

How do rechargeable batteries work?

Answer 4

When they are plugged into the power, the reaction reverses, which regenerates the original reactants

Question 5

Equation in a hydrogen fuel cell?

Answer 5

2H2 + O2 -> 2H2O

Question 6

Advantages of hydrogen fuel cells? (3)

Answer 6

• don’t need to be electronically recharged
• no pollutants produced
• can be a range of sizes for different uses

Question 7

Disadvantages of hydrogen fuel cells? (3)

Answer 7

• Hydrogen is highly flammable
• Hydrogen for the cells is sometimes produced by non-renewable sources
• Hydrogen is difficult to store

Question 8

Equation for reaction at cathode of h fuel cell?

Answer 8

2H2 (g) + 4OH- (aq) -> 4H2O (l) +4e-

Question 9

Equation for reaction at anode of h fuel cell?

Answer 9

O2 (g) + 2H2O (l) +4e- -> 4OH- (aq)

Question 10

Hydrogen is an….

Answer 10

alternative fuel

Question 11

How do hydrogen fuel cells work?

Answer 11

Hydrogen is oxidised and provides a source of electrons in the cell, and produces water as the waste product