Questions Corrections 2018

Question 1

Give a substance that can react with an acid to form a soluable salt

Answer 1

Alkali

Question 2

What should be added in excess to make pure dry crystals the metal oxide or the acid?

Answer 2

The metal oxide

Question 3

Why do alkaline batteries eventually stop working

Answer 3

Reactants are used up

Question 4

Why can alkaline batteries not be recharged

Answer 4

The reaction is not reversible

Question 5

Reasons why fuel cells are better than rechargeable batteries

Answer 5

Time for refuelling a fuel cell is faster than recharging
Hydrogencan be renewable if made by electrolysis using renewable energy
Lithium ion batteries can catch fire
Hydrogen has produces only water
Lithium ion batteries may release toxic chemicals on disposal

Question 6

Reasons why lithium ion rechargeable battery could be judged as better

Answer 6

Uses energy more efficiently and cost of car is less
Hydrogen often made from fossil fuels so not renewable
Hydrogen is highly flammable and difficult to store
Has a finite life (as catalyst eventually becomes poisoned)

Question 7

Why should the student use a pipette to measure the dilute sulfuric acid and a burette to measure the sodium hydroxide solution

Answer 7

Pipette measures a fixed volume accurately
But burette measures variable volume