The density (in g ~mL^ -1 ) of a 3.60 ~M sulphuric acid solution...

Let the density of solution be ' $\mathrm{d}$ ' Molarity of solution given $=3.6$ i.e. $1$ litre of solution contains $3.6$ moles of $\mathrm{H}_2 \mathrm{SO}_4$ or $1$ litre of solution contains $3.6 \times 98 \mathrm{~gms}$ of $\mathrm{H}_2 \mathrm{SO}_4$ Since, the solution is $29 \%$ by mass. $100 \mathrm{~gm}$ solution contains $29 \mathrm{~gm} \mathrm{~H}_2 \mathrm{SO}_4$ $\frac{100}{\mathrm{~d}} \mathrm{ml}$ solution contains $29 \mathrm{~gm}$ of $\mathrm{H}_2 \mathrm{SO}_4$ $1000 \mathrm{~ml}$ solution contains $3.6 \times 98 \mathrm{~gm}$ of $\mathrm{H}_2 \mathrm{SO}_4$ $\therefore 3.6 \times 98=\frac{29 \times \mathrm{d}}{100} \times 1000$ $d=1.22$ Hence, (C) is correct.