Which one has the highest percentage of nitrogen?

Define Percentage Composition in a compound.

Provide information on the percentage proportion of elements and mixtures present in Portland cement.

Calculate the mass percent of different elements present in sodium sulphate $(Na_{2}SO_{4})$.

$A$ welding fuel gas contains carbon and hydrogen only. Burning a small sample of it in oxygen gives $3.38 \ g$ of carbon dioxide,$0.690 \ g$ of water and no other products. $A$ volume of $10.0 \ L$ of this welding gas (measured at $STP$) is found to weigh $11.6 \ g$. Calculate: $(i)$ Empirical formula,$(ii)$ Molar mass of the gas,$(iii)$ Molecular formula.

Among the following,the compound with the highest percentage of chlorine is: