Question

Molarity is defined as:

• A. The number of moles of solute dissolved in 1 ${\mathrm{dm}}^3$ of the solution.
• B. The number of moles of solute dissolved in $1\mathrm{kg}$ of solvent.
• C. The number of moles of solute dissolved in 1 ${\mathrm{dm}}^3$ of the solvent.
• D. The number of moles of solute dissolved in $100\mathrm{mL}$ of solvent.

Answer 1

The correct option is A

The number of moles of solute dissolved in 1 ${\mathrm{dm}}^3$ of the solution.

Explanation for correct answers:

Option A The number of moles of solute dissolved in 1 ${\mathrm{dm}}^3$ of the solution.

• Molarity$\left(\mathrm{M}\right)$ of a given solution which means the concentration of the solution can be defined as the total number of moles of solute per liter of solution.
• It is also termed molar concentration.
• The units of molarity are $\mathrm{mol}{\mathrm{dm}}^{-3}$, $\mathrm{mol}{\mathrm{l}}^{-1}$.
• One molar solution means one gram of solute dissolved in a liter of solution.
• That is the number of moles of solute dissolved in 1 ${\mathrm{dm}}^3$ of the solution.
• The formula to find the molarity is $\mathrm{M}=\frac{\mathrm{n}}{\mathrm{V}}$ Where, '$\mathrm{M}$‘ is Molality of the solution, ’$\mathrm{n}$' Number of moles of the solute, and '$\mathrm{V}$' Volume of solution given in terms of litres.
• Hence option A is correct.

Option B The number of moles of solute dissolved in $1\mathrm{kg}$ of solvent.

• The number of moles of solute dissolved in 1 litre of solution is known as molarity.
• Hence option B is incorrect.

Option C The number of moles of solute dissolved in 1 ${\mathrm{dm}}^3$ of the solvent.

• The number of moles of solute dissolved in 1 litre of solution is known as molarity.
• Hence option C is incorrect.

Option D The number of moles of solute dissolved in $100\mathrm{mL}$ of solvent.

• The number of moles of solute dissolved in 1 litre not $100\mathrm{mL}$ of the solution is known as molarity.
• Hence option D is incorrect.