Question

5.15 gram NaBr is dissolved in 500 mL of solution.
Find out molarity of the solution.​

Answer 1

Given:-

• Mass of NaBr is 5.15 gram.

• Volume of solution is 500 ml.

To Find:-

• Molarity ( m ) of the solution.

Solution:-

Here, Molarity ( m ) ⇒ $\dfrac{Number \ of \ moles \ of \ Solute}{Volume \ of \ solution \ in \ Litres}$

So, Number of moles in NaBr ⇒ $\dfrac{weight \ of \ NaBr}{mass \ of \ NaBr}$

                                                 ⇒ $\dfrac{5.15 \ g}{102.89 \ g}$

                                                 ⇒ 0.05 moles

Here, Volume of solution in Litre = $\dfrac{500}{1000}$ = 0.5 Litre

Now, Molarity ( M ) ⇒ $\dfrac{0.05 \ moles}{0.5 \ l}$

                               ⇒ 0.1 M

Hence, Molarity of the solution is 0.1 M.

Some Important Terms:-

• Normality = $\dfrac{Mass \ of \ solute}{Mass \ of \ solution}$

• Molality = $\dfrac{Number \ of \ moles \ of \ Solute}{Weight \ of \ solvent} \times 1000$

• Molarity = $\dfrac{Number \ of \ moles \ of \ Solute}{Volume \ of \ solution \ in \ Litres}$