100 ml of ethyl alcohol [d = 0.92 g/ml] and 900 ml of water [d = 1 g/ml] are mixed to form 1 lit solution. The Molarity and molality of the resulting solution are

Wt. of ethyl alcohol(solute)=0.92x100=92gm

Volume of solution= 1000ml

Wt. of solvent(a)= 900x1=900gm

 $$\begin{gathered} \mathrm{M}=\frac{{\mathrm{W}}_{\mathrm{s}}}{{\mathrm{M}}_{\mathrm{s}}}\times \frac{1000}{\mathrm{V}\left(\mathrm{ml}\right)}=\frac{92}{46}\times \frac{1000}{1000}=2\mathrm{M} \\ \mathrm{m}=\frac{{\mathrm{W}}_{\mathrm{s}}}{{\mathrm{M}}_{\mathrm{s}}}\times \frac{1000}{\mathrm{a}\left(\mathrm{gm}\right)}=\frac{92}{46}\times \frac{1000}{900}=2.22\mathrm{m} \end{gathered}$$