The density at `20^(@)C` of a 0.5 solution of acetic acid in water is `1.0042` g/m L. The molality of the solution

Options

A. `0.50m`
B. `0.613m`
C. `0.513m`
D. `0.48m`

Answer

C

Explanation

Let , volume of solution `=1000m L` Moles of solute `=0.5`
`therefore` Weight of acetic acid `=0.5xx60g=30g`
Mass of solution = volume of solution x density
`therefore = 1000m L xx1.0042g//m L `
`therefore` Mass of solution `=1004.2g`
Mass of solvent `=1004 .2g-30g`
`therefore =974.2g`
Molality `=(1000xx"moles of solute")/("mass of solvent")=(1000xx0.5)/(974.2)`
`therefore` Molality `=0.513 m`