C5

Question 1

What is an example of an endothermic reaction?

Answer 1

Thermal decomposition
Citric acid + baking soda

Question 2

What is an example of an exothermic reaction?

Answer 2

Combustion
Neutralisation
Oxidation
Hand Warmers

Question 3

What is an example of using exothermic things

Answer 3

Hand warmers (iron oxide releases energy)

Question 4

Are Sports injury packs endothermic or exothermic?

Answer 4

Endothermic
When squeezing, the ammonium nitrate and water mix in the pack causing cooling

Question 5

How are cells connected together in a battery?

Answer 5

In series

Question 6

What are rechargeable batteries

Answer 6

Batteries where electric current reverses the reaction at the electrode

Question 7

What are non-rechargeable batteries?

Answer 7

Batteries where the current is irreversible at the electrode

Question 8

Advantages of using fuel cells

Answer 8

Less pollution
High efficiency
Compact and Lightweight
Reliable

Question 9

What happens in an oxidation reaction?

Answer 9

Hydrogen is pumped at the anode
Oxygen is pumped at the cathode
Water is produced

Question 10

Disadvantages of batteries compared to hydrogen fuel cells

Answer 10

Cause pollution
Must be replaced after a certain number of recharges
Inferior capacity to store energy so has to be recharged a lot more

Question 11

Disadvantage of hydrogen fuel cells

Answer 11

Has to be stored at high pressure and highly explosive