$0.92 \mathrm{g}$ of an organic compound containing carbon, hydrogen and oxygen was analysed by the combustion method. The increase in mass of the $\mathrm{U}$-tube and the potash bulbs at the end of the operation was found to be $1.08 \mathrm{g} \text{and} 1.76 \mathrm{g}$, respectively. Determine the percentage composition of the compound.

An organic compound on analysis gave the following data:
(i) $0.25 \mathrm{gm}$ of the compound on complete combustion gave $0.37 \mathrm{gm}$ of ${\mathrm{CO}}_2$ and $0.2 \mathrm{gm}$ of water.

(ii) $0.25 \mathrm{gm}$ of the compound on analysis by Duma's method gave $32 \mathrm{ml}$ of nitrogen gas at $\mathrm{STP}$.

Calculate the percentages of $\mathrm{C}, \mathrm{H}, \mathrm{N} \text{and} \mathrm{O}$ in the organic compound.

An organic compound on analysis gave the following data:

(ii) $0.25 \mathrm{g}$ of the compound on analysis by Duma's method gave $32 \mathrm{mL}$ of nitrogen gas at $\mathrm{STP}$. Calculate the percentages of $\mathrm{N}$ and $\mathrm{O}$ in the organic compound if the percentage of the carbon and hydrogen is $40.36 \%$ and $8.9\%$ respectively.

$0.5 \mathrm{g}$ of an organic compound on Kjeldahl's analysis gave enough ammonia to just neutralize $10 {\mathrm{cm}}^3$ of $1 \mathrm{M}$${\mathrm{H}}_2{\mathrm{SO}}_4$.The percentage of nitrogen in the compound is:

(Atomic mass: $\mathrm{N}=14, \mathrm{H}=1$)

In an experiment $0.22 \mathrm{g}$ of magnesium pyrophosphate was produced from $0.1 \mathrm{g}$ of an organic compound. The percentage of phosphorus in it is:

(Atomic mass: $\mathrm{Mg}=24, \mathrm{P}=31, \mathrm{O}=16$)