The amount of water that should be added to 500 ml of 0.5 N solution of NaOH to give a concentration of 10 mg per ml is

Options

A. (a)100
B. (b)200
C. (c )250
D. (d)500

Answer

D

Explanation

`N_(1)=0.5 N rarr 10 g per ml`
`N_(2)=(10xx10^(-3)g)/(40xx1)xx1000=0.25 N`
`V_(1)=500 ml, V_(2)=?`
`N_(1)V_(1)=N_(2)V_(2), 0.5xx500=0.25xxV_(2)`
`V_(2)=1000 ml`
final volume water added`=1000-500=500 mL`.