What is the value of percent atom economy if the molar mass of reactants is $36 \ u$ and the mass of the desired product is $27 \ u$ (in $\%$)?

If isobutane and $n$-butane are present in a gas,then how much oxygen should be required for the complete combustion of $5 \ kg$ of this gas?

If a mixture of $340 \ g$ of $N_2$ and $H_2$ in the stoichiometric ratio yields $20\%$ $NH_3$ by mass,what is the mass of $NH_3$ produced in $g$?

The volume of water to be added to $100 \, cm^3$ of $0.5 \, N \, H_2SO_4$ to get decinormal concentration is ........ $cm^3$.

$5 \ mL$ of $N \ HCl$,$20 \ mL$ of $N/2 \ H_2SO_4$,and $30 \ mL$ of $N/3 \ HNO_3$ are mixed together and the volume is made up to $1 \ L$. The normality of the resulting solution is:

$A$ sample of $NaNO_3$ weighing $0.38 \ g$ is placed in a $50.0 \ mL$ volumetric flask. The flask is filled to the mark with water. What is the molarity of the solution?