Chemistry Past Questions and Answers

When hydrogen sulphide and sulphur dioxide are each passed in turn into a solution of potassium dichromate?

Which one of the following metals is not normally extracted by chemical reduction because of its position in the electrochemical series?

If one mole of aluminium contains 6 x 10²³ atoms of aluminium, how many atoms are contained in 0.9g of aluminium?
(Al = 27)

4g each of aluminium foil and aluminium powder were introduced respectively into flasks P and Q.
Flask P was treated with warm bench sodium hydroxide and all the aluminium dissolved in one hour. Flask Q was treated with cold sodium hydroxide and all the aluminium dissolved in 10 minutes. What was responsible for Q reacting faster than P?

What happens when the nitrates of potassium, calcium, zinc and copper are separately heated?