# Question 7a5fb

Apr 23, 2017

In 1 L of solution you would have (a) 150 g, (b) 167 g, and (c) 325 g of $\text{NaCl}$.

#### Explanation:

Assume that you have 1 L of solution.

(a) 15 % w/v

$\text{Mass of NaCl" = 1000 color(red)(cancel(color(black)("mL solution"))) × "15 g NaCl"/(100 color(red)(cancel(color(black)("mL solution")))) = "150 g NaCl}$

(b) 15 % w/w

The density of a 15 % w/w NaCl solution is 1.1135 g/mL.

Thus, the mass of 1 L of this solution is

1000 color(red)(cancel(color(black)("mL"))) × "1.1135 g"/(1 color(red)(cancel(color(black)("mL")))) = "1113.5 g"#

$\text{Mass of NaCl" = 1113.5 color(red)(cancel(color(black)("g solution"))) × "15 g NaCl"/(100 color(red)(cancel(color(black)("g solution")))) = "167 g NaCl}$

(c) 15 % v/v

This unit is usually used for solutions of liquids in liquids. However,

$\text{Volume of NaCl" = 1000 color(red)(cancel(color(black)("cm"^3 color(white)(l)"solution"))) × ("15 cm"^3 color(white)(l)"NaCl")/(100 color(red)(cancel(color(black)("cm"^3color(white)(l) "solution")))) =150 color(white)(l)"cm"^3 "NaCl}$

$\text{Mass of NaCl" = 150 color(red)(cancel(color(black)("cm"^3 color(white)(l)"NaCl"))) × "2.165 g NaCl"/(1color(red)(cancel(color(black)("cm"^3color(white)(l) "NaCl")))) = "325 g NaCl}$