What volume of aqueous solution of NaOH that is `80%` by mass NaOH, contanis 0.4 mol of NaOH. Density of solution is `0.8 gm//ml`.

Options

A. `8 ml`
B. 25 ml
C. 16 ml
D. 250 ml

Answer

B

Explanation

`0.4 " mole " NaOH = 0.4 xx 40 = 16 gm`
`80%` by mass NaOH
`80 gm NaOH` in 100 gm solution
16 gm NaOH in 20 gm solution
Volume of solution `(V) = (m)/(d) = (20)/(0.8) = 25 ml`