Question

The number of moles of solute present in $600mL$ of $0.05M$ solution is $0.03mol$.
A: True
B: False

Answer 1

Hint: Molarity is the measure of number of moles of a solute that are present in one liter of a solution. Number of moles of a substance can be calculated by dividing the given mass of a substance with the molecular mass.

Formula used: Molarity$ = \dfrac{{{\text{number of moles }} \times 1000}}{{{\text{volume of solution in mL}}}}$


Complete step by step answer:
In this question we have given the molarity of a substance and volume of its solution and we have to verify the number of moles of solute. Molarity is defined as the number of moles of a solute that are present in one liter of a solution. The units of molarity is $M$. Number of moles of a substance can be calculated by dividing the given mass of a substance with the molecular mass of that substance. Formula to calculate molarity is,
Molarity$ = \dfrac{{{\text{number of moles }} \times 1000}}{{{\text{volume of solution in mL}}}}$
Molarity of solution is $0.05M$ (given)
Volume of solution is $600mL$ (given)
Substituting these values in the above formula we can calculate the number of moles of solute. So,
$0.05 = \dfrac{{{\text{number of moles }} \times 1000}}{{600}}$
Solving this we get,
Number of moles$ = \dfrac{{0.05 \times 600}}{{1000}} = 0.03$
Therefore, the number of moles of solute are $0.03$. Number of moles of solute that are given in the statement is $0.03mol$ which is equal to the number of calculated moles. Therefore, the given statement is correct. So, the correct answer is option A that is true.

Note:
Molality is defined as the number of moles that are present per kilogram of the solvent. In the calculation of molality the mass of solvent is used and in the calculation of molarity the volume of solution is used.