Question

If you needed to collect 263 g of NaCl salt by evaporating off the water from a 4.2% by mass solution of NaCl salt water, how many grams of the solution do you need to evaporate the water off of?

Answer 1

We have given,

Mass of $\text{NaCl}=236g$

Mass percent$=4.2$ %

Let the mass of solution be $x$

We know,

Mass%=$\dfrac{(\text{Mass of NaCl)}}{\text{(Mass of solution)}}\times 100$

$4.2=\dfrac{(263\times 100)}{x}$

$\implies x=\dfrac{26300}{4.2}\\\implies x=6261.90g$

Hence, $6261.90g$ of solution we need to evaporate the water off.