Worksheet 8.6C Acid on rocks Samia and Carlos want to investigate the effect of acids of different pHs on some rock. They have decided to put rocks into beakers of acid at pH 1, 2, 3, 4, 5 and 6. They will leave the rocks in the beakers for two days. Then they will remove the rocks and weigh them.

Which variable are Samia and Carlos changing?
2 Which variables do they need to keep the same?
3 What safety precautions do they need to take?
4 What do they need to do to the rocks before they start the investigation?
5 Construct a results table for this experiment.