The indicator used in a titration between strong acid and weak base is

Nitrogen obtained from air is not absolutely pure because it contains the following except

Solubility curve is a plot of solubility against 

If 11.0g of a gas occupies 5.6 dm\(^3\) at s.t.p., calculate its vapour density (1 mole of a gas occupies 22.4 dm\(^3\)).

The Van der waals forces of attraction operates between