Molarity (
) is defined as the number of moles of solute dissolved per liter of solution. It is the most common unit of concentration used in chemistry to express the strength of a solution.
The formula for Molarity is:

Where
is the number of moles and
is the volume.
1. Identify Moles and Volume
To calculate Molarity, you must first determine the amount of solute in moles (
) and the total volume of the solution (
).
Moles (
): Calculated by dividing the given mass (
) by the molar mass (
) of the solute:

.
Volume (
): Must be in Liters (
). If given in milliliters (
), divide by


.
2. Apply the Standard Formula
If the mass of the solute and the volume in
are provided, the combined formula is:

3. Consider Temperature Dependence
Molarity is temperature-dependent. Since volume expands or contracts with temperature changes, the Molarity of a solution will change if the temperature changes. This is a frequent conceptual question in NEET.
4. Use Dilution and Mixing Formulas
For NEET problems involving changing concentrations:
Dilution Formula: When water is added to a solution, the moles of solute remain constant:

Mixing Formula: When two solutions of the same solute are mixed:


5. Link with Density and Mass Percentage
Often, NEET questions provide density (
) and mass percentage (
w/w). The shortcut formula is:

Comparison Table for NEET
Property Description
Unit

or Molar (
)
Depends on Temperature? Yes (because it involves volume)
Relationship with Molality
is usually less than molality in aqueous solutions