$300 \ mL$ of a gaseous hydrocarbon when burnt in excess of $O_2$ gave $2.4 \ L$ of $CO_2$ and $2.7 \ L$ of water vapour under same conditions. The molecular formula of the hydrocarbon is:

If the enthalpy of combustion of anhydrous oxalic acid is $x \, kcal \, mol^{-1}$,then how much heat in $kcal$ will be produced by the combustion of $2 \, g$ of oxalic acid?

$C_2H_4$ can react with $H_2$ in the presence of a catalyst to form $C_2H_6$ as per the following reaction: $C_2H_{4(g)} + H_{2(g)} \xrightarrow{\text{Catalyst}} C_2H_{6(g)}$. The amount of $C_2H_4$ in grams required to produce $50 \ g$ of $C_2H_6$ is: (in $g$)

$4.0 \, g$ of caustic soda is dissolved in $100 \, mL$ of solution. The normality of the solution is: (in $, N$)

$14 \ g$ of element $X$ combines with $16 \ g$ of oxygen. Based on this,which of the following statements is incorrect?

Calculate the percent atom economy when a product of formula weight $175 \ u$ is obtained in a chemical reaction using $225 \ u$ formula weight reactant. (in $\%$)