Following Kjeldahl's method, $1 \mathrm{~g}$ of organic compound released ammonia, that neutralised $10 \mathrm{~mL}$ of $2 \mathrm{M} ~\mathrm{H}_2 \mathrm{SO}_4$. The percentage of nitrogen in the compound is ___________ $\%$.

Consider the following redox reaction :

$$ \mathrm{MnO}_4^{-}+\mathrm{H}^{+}+\mathrm{H}_2 \mathrm{C}_2 \mathrm{O}_4 \rightleftharpoons \mathrm{Mn}^{2+}+\mathrm{H}_2 \mathrm{O}+\mathrm{CO}_2 $$

The standard reduction potentials are given as below $\left(\mathrm{E}_{\text {red }}^0\right)$ :

$$ \begin{aligned} & \mathrm{E}_{\mathrm{MnO}_4^{-} / \mathrm{Mn}^{2+}}^{\circ}=+1.51 \mathrm{~V} \\\\ & \mathrm{E}_{\mathrm{CO}_2 / \mathrm{H}_2 \mathrm{C}_2 \mathrm{O}_4}^{\circ}=-0.49 \mathrm{~V} \end{aligned} $$

If the equilibrium constant of the above reaction is given as $\mathrm{K}_{\mathrm{eq}}=10^x$, then the value of $x=$ __________ (nearest integer)

Number of compounds which give reaction with Hinsberg's reagent is _________.

$10 \mathrm{~mL}$ of gaseous hydrocarbon on combustion gives $40 \mathrm{~mL}$ of $\mathrm{CO}_2(\mathrm{~g})$ and $50 \mathrm{~mL}$ of water vapour. Total number of carbon and hydrogen atoms in the hydrocarbon is _________ .