Question

Question #45686

Answer 1

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, `"NaOH"`, present in your solution.

So, I think that the question goes like this

How many moles of solute, `"NaOH"`, you get if the molarity is equal to `"1.0 M"` and the volume of the solution is `"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

`"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 `"0.05 L"` of solution

`0.05 color(red)(cancel(color(black)("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"color(white)(a/a)|)))`

So, a `"0.05-L"` sample of your `"1.0 mol L"^(-1)` sodium hydroxide solution will contain `0.05` moles of sodium hydroxide.