# Question 11d6b

Dec 8, 2014

The answer is $296.3 g$.

Saline solution is a mixture of table salt ($N a C l$) and water (${H}_{2} O$).
The solution's percent concentration by mass, defined as the mass of solute (in this case, $N a C l$) divided by the total mass of the solution and multiplied by 100%, is said to be 1.25%.

The total mass of the solution is equal to

${m}_{s o l u t i o n} = {m}_{N a C l} + {m}_{w a t e r}$

Knowing that c% = m_(solute)/(m_(solut ion)) * 100%, and that the

mass of the solution is $300 g$, we can determine the mass of $N a C l$ by

${m}_{N a C l} = \frac{c \cdot {m}_{s o l u t i o n}}{100} = \frac{1.25 \cdot 300}{100} = 3.75 g r a m s$

This means that the mass of water is equal to

${m}_{w a t e r} = {m}_{s o l u t i o n} - {m}_{N a C l} = 300 - 3.75 = 296.3 g r a m s$, which makes sense since the bulk of this particular solution must be represented by water, given the fact that its percent concentration by mass is 1.25%#.