The hydrated salt $Na_2SO_4 \cdot nH_2O$ undergoes $55.9 \%$ loss in weight on heating and becomes anhydrous. The value of $n$ will be?

What volume (in $mL$) of gaseous $NH_3$ at $N.T.P.$ is required to be passed into $30 \, mL$ of $1 \, N \, H_2SO_4$ solution to reduce the acid strength of this solution to $0.2 \, N$?

What is the mass in $g$ of $70\%$ $H_2SO_4$ required for the neutralization of $1$ mole of $NaOH$?

Calculate the concentration of nitric acid in moles per litre in a sample which has a density of $1.41 \, g \, mL^{-1}$ and the mass percent of nitric acid in it is $69 \%$.

What is the value of percent atom economy when an organic compound of formula weight $75 \ u$ is obtained from reactants having sum formula weight $225 \ u$?

If $1/2 \text{ mole of oxygen reacts with aluminum to form } Al_2O_3, \text{ the mass of aluminum metal consumed in the reaction is } ..... \text{ g. } (Al=27)$