On complete combustion,$0.492 \ g$ of an organic compound gave $0.792 \ g$ of $CO_2$. The $\%$ of carbon in the organic compound is $..................$ (Nearest integer)

In the crystalline solid $MSO_{4} \cdot nH_{2}O$ of molar mass $250 \ g \ mol^{-1}$, the percentage of anhydrous salt is $64$ by weight. The value of $n$ is

Carbon percentage is maximum in

The percentage of oxygen in $NaOH$ is (in $\%$)

An organic compound contains $C = 74.0\%$,$H = 8.65\%$ and $N = 17.3\%$. Its empirical formula is:

An organic compound with a molecular weight of $60$ contains $C = 20\%$,$H = 6.67\%$,and $N = 46.67\%$,with the remainder being oxygen. Upon heating,the solid residue gives a violet color with alkaline copper sulfate solution. Identify the compound.