Question

A solution is composed of $80.00g$ of sodium hydroxide dissolved in $2.0L$. Find out the molarity of the solution ?

• A. $1.0M$
• B. $2.0M$
• C. $4.0M$
• D. $40.0M$
• E. $160.0M$

Answer 1

The correct option is A $1.0M$

Molarity of solution is the number of moles of solution divided by the volume of solution in L.
Number of moles of solute are obtained by dividing mass of solute with molar mass.
The molar mass of NaOH is 40.00 g/mol.
Number of moles $=\frac{80.00g}{40.00g/mol}=2.0mol$
Molarity $=\frac{2.0mol}{2.0L}=1.0M$