Question

The molar mass of NaOH is 40.00 g/mol. If 5.20 g NaOH are dissolved in 0.500 L of solution, what is the molarity of the solution?

Answer 1

Answer is 0.26

Molarity of the solution is 

[ 5.20g / 0.5L ] x [1mole / 40.00g] =0.26

Answer 2

Answer: The molarity of the solution is 0.26M

Explanation: Molarity of the solution is defined as the number of moles of solute present in a liter volume of solution.

Mathematically,

$Molarity=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}$

Number of moles is expressed by using the formula:

$Moles=\frac{\text{Given mass}}{\text{Molar mass}}$

Putting this in above equation, we get:

$Molarity=\frac{\text{Given mass of solute (in grams)}}{\text{Molar mass of solute}\times\text{volume of solution (in L)}}$

Given mass of solute (NaOH) = 5.20 g

Molar mass of solute (NaOH) = 40 g/mol

Volume of solution = 0.500 L

Putting values in above equation, we get:

$Molarity=\frac{5.20g}{40g/mol\times 0.5L}=0.26mol/L$