Acids

Question 1

State the colour of Universal indicator in a solution of ethanoic acid.

Answer 1

Yellow, orange or red.

Question 2

State the general equation for the reaction of an acid with a base.

Answer 2

acid + base -> salt + water

Question 3

Magnesium carbonate reacts with dilute nitric acid.

Give the names of the products formed in this reaction.

Answer 3

Magnesium nitrate, water and carbon dioxide.

Question 4

Write the general word equation for. the reaction between an acid and:

1) Metal
2) Metal oxide

Answer 4

1) metal + acid -> metal salt + hydrogen

2) metal oxide + acid -> metal salt + water

Question 5

Describe what you would see when copper carbonate powder is added to dilute sulphuric acid.

Answer 5

Green solid dissolves, bubbles of colourless gas are given off and a blue solution is formed.

Question 6

Describe how solid magnesium oxide and dilute sulphuric acid are used to prepare a sample of pure magnesium sulfate solution.

Answer 6

Add excess magnesium oxide to the acid, filter it and then crystallise the solution.

Question 7

A solution of hydrochloric acid is pH 1. Explain the pH change when 10cm cubed of this acid is diluted with water to make 100cm cubed of solution.

Answer 7

Acid is diluted 10 times, this. causes increase in pH by 1, it becomes pH 2.

Question 8

write the general word equation for the reaction between a metal carbonate and an acid.

Answer 8

Metal carbonate + acid ->

metal salt + water + carbon dioxide

Question 9

Write the ionic equation for the reaction between metal carbonate and hydrochloric acid.

Answer 9

2H+ (aq) + CO3^2- (s) -> H2O(l) + CO2(g)

Question 10

Zinc reacts with dilute hydrochloric acid. Write the half equation to show what happens to zinc atoms.

Answer 10

Zn(s) -> Zn2+ (aq) + 2e