Rubidium, Rb, is a Group I element. It has similar physical and chemical properties to the other elements in Group I.
When rubidium is added to cold water a reaction occurs.
Suggest one safety measure that should be used when rubidium is added to cold water.
Solid R reacted with dilute sulfuric acid.
The initial temperature of the dilute sulfuric acid and the final temperature of the solution are shown.
initial temperature of the dilute sulfuric acid
What was the change in temperature in ?
-6
-4
4
6
Ethanoic acid is a weak acid and hydrochloric acid is a strong acid.
Both ethanoic acid and hydrochloric acid dissociate in aqueous solution.
A student does experiments to show that hydrochloric acid is a strong acid and ethanoic acid is a weak acid. The student adds an excess of hydrochloric acid and an excess of ethanoic acid to separate samples of lumps of calcium carbonate.
Only the identity of the acid is changed between the experiments. All other conditions are kept the same.
The student uses the same size container and checks that the pressure is the same for each experiment.
State three other conditions which must be kept the same to ensure fair testing.
1
2
3
Sulfuric acid is produced by the Contact process. The steps of the Contact process are shown.
Dilute sulfuric acid is a typical acid.
A student adds excess dilute sulfuric acid to a sample of solid copper(II) carbonate in a test-tube.
Give three observations the student would make.