Question

Equal masses of water and a liquid of relative density $2$ are mixed together, then the mixture has a density (in $gc{m}^{-3})$ of :

• A. $\frac{2}{3}$
• B. $\frac{4}{3}$
• C. $\frac{3}{2}$
• D. $3$

Answer 1

The correct option is B $\frac{4}{3}$

let mass of liquid and water be x gm.

density of water = 1 g$c{m}^{-3}$

Relative density = $\frac{{\rho }_{\left(liquid\right)}}{{\rho }_{\left(water\right)}}$ = 2

so density of liquid = 2 g$c{m}^{-3}$

Volume of water = $\frac{x}{1}$cc = x $c{m}^3$

Volume of liquid = $\frac{x}{2}$ $c{m}^3$

hence total volume = $\frac{3x}{2}$

total mass x + x = 2x

hence density of mixture = $\frac{2x}{3x\times .5}$ = $\frac{4}{3}$

so option (B) is correct