The sensation of fatigue in the muscles after prolonged strenuous physical work is caused by–

What is the number of water molecules present in a Ferrous Sulphate crystal

Bee sting leaves an acid which causes pain and irritation. The acid released is

The chemical used as a 'fixer' in photography is –

Which one of the following acid is used by goldsmith for cleaning of gold and silver articles?

The chemical used for destroying fungi in water tank is