Question

A $10$% solution of $NaCl$ means that in $100g$ of solution there is:

• A. $5.85g$ $NaCl$
• B. $58.5g$ $NaCl$
• C. $10g$ $NaCl$
• D. $94g$ $NaCl$

Answer 1

Answer: (C)

$10g$ $NaCl$

A $10$% solution of $NaCl$ means that in $100g$ of solution there is $10g$ $NaCl$.

Let W g of $NaCl$ are present in $100g$ of $10$% solution.

$\text{Percent by mass}=\frac{\text{Mass of NaCl}}{\text{Mass of solution}}\times 100$

$\text{10}=\frac{\text{Mass of NaCl}}{\text{100 g}}\times 100$

$\text{Mass of NaCl}=\text{10 g}$