Question

What is molarity?
A. Moles of solute per liter of solution
B. Mass of solvent per liter of solution
C. Mass of solvent per liter of solution
D. Mass of solute per kg of solution
E. Moles of solute per kg of solution

Answer 1

Hint: Molarity and molality are units to measure the concentration of the solutions. The main difference between molarity and molality comes with mass versus volume. In molarity we are going to use volume of the solution and in molality we are going to use mass of the solution.

Complete step by step answer:
- Molarity is also called molar concentration of the solution.
- Molarity can be defined as the amount of solute present in a known volume of the solution. It is nothing but moles of solute present in a liter of the solution.
- Molarity is going to be denoted with a symbol M.
- There is a formula to calculate the molarity of the solution.
- The formula of molarity of the solution is as follows.
$$M={\displaystyle \frac{W}{MW}}\times {\displaystyle \frac{1000}{V(ml)}}$$
W = weight of the solute
MW = molecular weight of the solute
V = volume of solvent in ml.
- Therefore molarity is nothing but Moles of solute per liter of solution.

- So, the correct option is A.


Note: Molality is different from molarity.
Molality can be defined as moles of the solute present per kg of the solution. Molality is going to be denoted with a symbol m. The units for molality are m or mol/kg.