Practice Questions 3

Question 1

If there was yellow coloured negative ions in an electrolysis reaction why would the colour cha he at the positive electrode

Answer 1

Opposites attract and the negative ion is yellow coloured

Question 2

The gas at the positive electrode was oxygen

The oxygen was produced by hydroxide ions

Name th substance in the solution the provides the hydroxide ions

Answer 2

Water

Question 3

How do solids form at the negative electrode

Answer 3

The copper ion gains two electrons and creates copper atoms

Question 4

Name the product at each electrode when potassium iodide solution is electrolysed

Answer 4

Negative electrode:hydrogen

Positive electrode:iodine

Question 5

What is activation energy

Answer 5

The minimum energy needed for particles to react

Question 6

Finish this equation

Mg(s) + Zn^2(aq)——>

Answer 6

Mg^2(aq) + Zn(s)

Question 7

Why is the reaction between magnesium ions and zinc ions both oxidation and reduction

Answer 7

Magnesium atoms are oxidised due to then losing electrons

And zinc ions are reduced because they gain electrons

Question 8

07.1 diagram what are the two errors?

Answer 8

The activation energy should be starting from the reactants

The products should have less energy than the reactants

Question 9

What are two advantages to using hydrogen fuel cells instead of rechargable cells to power cars

Answer 9

No toxic chemicals in hydrogen fuel cells

Hydrogen fuel cells allow you to travel farther without recharging

Question 10

Reactions occur at the positive electrode and at the negative electrode in a hydrogen fuel cell.

Write a half equation for one of these reactions

Answer 10

H2——>2H^+. +. e^-