The organic compound has the molar mass $108 \mathrm{g} \mathrm{mol}{}^{-1}.$ The $\mathrm{C}, \mathrm{H}$ and $\mathrm{N}$ atoms are present in the ratio of  $9:1:3.5$ by weight. What is the molecular formula of organic compound?

What volume of hydrogen gas at $273\mathrm{K}$ and $1\mathrm{atm}$pressure will be consumed in obtaining $21.6 \mathrm{g}$ of elemental boron (atomic mass $=10.8$) from the reduction of boron trichloride by hydrogen?

In the reaction,

 $2{\mathrm{Al}}_{\left(\mathrm{s}\right)}+6{\mathrm{HCl}}_{\left(\mathrm{aq}\right)}⟶2{\mathrm{A}}_{\left(\mathrm{aq}\right)}^{3+}+6{\mathrm{C\Gamma }}_{\left(\mathrm{aq}\right)}+3{\mathrm{H}}_2\left(\mathrm{g}\right)$.

Among the given statements, which is the true statement ?
 

What is the density (in ${\mathrm{gmL}}^{-1}$) of a $3.60 \mathrm{M}$ sulphuric acid solution that is $29\%\left({\mathrm{H}}_2{\mathrm{SO}}_4\right.$ molar mass $=98 \mathrm{g} {\mathrm{mol}}^{-1})$ by mass ?