# Question #45686

Apr 15, 2016

Here's my take on this.

#### Explanation:

I'm not really sure I understand what you're asking here, but I'll try to make an educated guess.

A solution's molarity tells you many moles of solute you get per liter of solution. You cannot use molarity to find liters of solute, so I assume that you're interested in finding the number of moles of sodium hydroxide, $\text{NaOH}$, present in your solution.

So, I think that the question goes like this

How many moles of solute, $\text{NaOH}$, you get if the molarity is equal to $\text{1.0 M}$ and the volume of the solution is $\text{0.05 L}$?

The interesting thing about molarity is that you can use it as a conversion factor to go from volume to moles of solute and vice versa.

Your solution is said to have a molarity of

${\text{1.0 M" = "1.0 mol L}}^{- 1}$

This tells you that one liter of this solution contains $1.0$ mole of sodium hydroxide, your solute. You can thus use this value to figure out how many moles of solute you'd get in $\text{0.05 L}$ of solution

$0.05 \textcolor{red}{\cancel{\textcolor{b l a c k}{\text{L solution"))) * overbrace("1.0 mole NaOH"/(1 color(red)(cancel(color(black)("L solution")))))^(color(purple)("= 1.0 mol L"^(-1))) = color(green)(|bar(ul(color(white)(a/a)"0.05 moles NaOH} \textcolor{w h i t e}{\frac{a}{a}} |}}}$

So, a $\text{0.05-L}$ sample of your ${\text{1.0 mol L}}^{- 1}$ sodium hydroxide solution will contain $0.05$ moles of sodium hydroxide.