The formula for calcium chlorite is

$A$ compound contains $10^{-2} \%$ of phosphorus. If the atomic mass of phosphorus is $31$,the molecular mass of the compound having one phosphorus atom per molecule is :-

What is the percentage of carbon in urea (in $\%$)? $(At. mass C = 12, H = 1, N = 14, O = 16)$

$A$ $400 \ mg$ iron capsule contains $100 \ mg$ of ferrous fumarate,$(C_2H_2O_4)Fe$. The percentage of iron present in it is approximately $.......... \%$.

On complete combustion of $0.492 \ g$ of an organic compound containing $C, H$ and $O$,$0.7938 \ g$ of $CO_2$ and $0.4428 \ g$ of $H_2O$ were produced. The percentage composition of oxygen in the compound is $........$

$A$ 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.