List of top Chemistry Questions on Qualitative Analysis asked in WBJEE

Which one of the following cations gives a chocolate brown precipitate upon addition of aqueous solution of \(\text{K}_4[\text{Fe}(\text{CN})_6]\)?
A compound (X) when treated with \( \text{CuSO}_4 \) solution yields a brown precipitate. On adding hypo solution the precipitate turns white. The compound (X) is

Kjeldahl's method cannot be used for the estimation of nitrogen in which compound? 

The compound that does not give a positive test for nitrogen in Lassaigne’s test is
Which pair of ions among the following can be separated by precipitation method?