# How many grams of NaOH are contained in 5.0 x 102 mL of a 0.77 M sodium hydroxide solution? The...

## Question:

How many grams of NaOH are contained in 5.0 {eq}\times {/eq} 10{eq}^2 {/eq} mL of a 0.77 M sodium hydroxide solution? The molar mass of NaOH is 40.0 g/mol.

## Molar Mass:

The molar mass is a property of substances wherein it provides the measurement of the mass per mole of the substance. We can use this quantity in order to determine how much of the reagent must be weighed in order to acquire the required number of moles of the substance.

Determine the mass of {eq}\displaystyle NaOH {/eq} in the given solution by first finding the number of moles of {eq}\displaystyle NaOH {/eq} there is in the given solution by multiplying the volume, {eq}\displaystyle V {/eq} to the molarity, {eq}\displaystyle M {/eq} or {eq}\displaystyle n = MV {/eq}, and then multiplying the number of moles to the molar mass of {eq}\displaystyle NaOH {/eq}. We proceed with the solution.

{eq}\begin{align} \displaystyle m_{NaOH} &= n\times 40.0\ \rm{g/mol}\\ &= MV \times 40.0\ \rm{g/mol}\\ &= 0.77\ M\ NaOH\times 0.50\ L \times 40.0\ \rm{g/mol}\\ &= 15.4\ g\ NaOH\\ &\approx \boxed{15\ g\ NaOH} \end{align} {/eq}