• # question_answer 11) A litre of water was evaporated from 8L of salt solution containing 8% salt. The percentage of salt left in the remaining solution is A)  $7\frac{1}{7}%$                                 B)  $7\frac{1}{9}%$          C)  $9\frac{1}{7}%$D)  $7\frac{1}{3}%$

(c): % age means $\frac{\text{weight}}{\text{volume}}%\text{ }age\Rightarrow$ in 100 ml, Salt being non-volatile, will not evaporate In 81, we have $8000ml\Rightarrow \frac{8}{100}\times 8000$gm salt = 640 gm salt. After evaporation 7L solution is left with same 640 gm salt $=\frac{W}{V}%=\frac{640\,gm}{7000\,mL}\times 100%=9\frac{1}{7}%$.