The fractional distillation is used in

The empirical formula of a compound is CH₂O. If its vapour density is 90, then the molecular formula of the compound is

An organic substance on analysis was found to contain 10.06 percent carbon, 0.84 percent hydrogen and 89.10 percent chlorine. Its empirical formula is

A liquid decomposes at its normal pressure. It can be purified by

Steam distillation is used for the purification of

The compound formed in the positive test for nitrogen with the Lassaigne’s solution of an organic compound is

Which of the following pair of species has the same percentage of carbon ?

The two impure substances, which do not have large differences in their solubilities, are purified by

When some pieces of human hair are heated strongly with soda-lime, smell of ammonia can be detected. Which of the following conclusion can be drawn from this observation ?

The most suitable method for the separation of a 1:1 mixture of ortho- and para- nitrophenols is