Water vapours when passed over anhydrous copper sulphate, the colour changes from:

From the list provided below choose the ones that match the description given.
Ferrous sulphate, Copper carbonate, Triferric tetroxide, Trilead tetroxide, Sulphur dioxide, Carbon dioxide, Lead nitrate, Zinc nitrate, Oxygen, Nitrogen,

A colourless gas which turns lime water milky but has no effect on acidified potassium dichromate paper.

The chemical equation for the combustion of ethane is
$2\mathrm{}{\mathrm{C}}_2{\mathrm{H}}_6+7{\mathrm{O}}_2\to 4\mathrm{}{\mathrm{C}\mathrm{O}}_2+6\mathrm{}{\mathrm{H}}_2\mathrm{O}$
$60\mathrm{}\mathrm{g}$ of ethane was completely burnt in oxygen. Answer the following question:

How would you test the presence of water as a product of this reaction?

Copper (II) carbonate is a green solid which decomposes on heating to form _____ gas.

(Write the name of the gas.)

What do you observe:

Sulphur dioxide is passed through acidified ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ solution.