Question

What is the molarity of an 18 L solution with 64 grams of sodium chloride dissolved in it?

Answer 1

Answer: 0.06 M

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.

$Molarity=\frac{n}{V_s}$

where,

n= moles of solute  $NaCl$

$Moles=\frac{\text{Given mass}}{\text{Molar mass}}=\frac{64g}{58.5g/mol}=1.09moles$  

$V_s$ = volume of solution  in Liters = 18 L

Putting in all the values we get,

$Molarity=\frac{1.09moles}{18L}=0.06M$

Thus the molarity of solution is 0.06 M

Answer 2

Molarity = moles of solute / liter of solution

in your case ,

1) liter of solution is = 18 L

2) mole of solute(NaCl) = gram/molar mass = 64/58.44= 1.095

Now you can put both values from 1 and 2 in the first equation to calculate the Molarity