Molarity is the concentration of a solution expressed as the number of moles of solute present in one litre of solution.

Quick Scoop: What is called molarity?

  • Molarity (symbol: M) is defined as:

Molarity (M)=moles of solutevolume of solution in litres\text{Molarity (M)}=\frac{\text{moles of solute}}{\text{volume of solution in litres}}Molarity (M)=volume of solution in litresmoles of solute​

  • “Solute” = the substance being dissolved (like salt, sugar, acid).
  • “Solution” = solute + solvent together (for example, salt + water mixture).
  • Unit of molarity is mol/L (read as “moles per litre”) and a solution of 1 mol/L is called “1 molar” or “1 M”.

Tiny example to picture it

  • If you dissolve 1 mole of NaCl (table salt) in enough water to make the total solution volume exactly 1 litre, its molarity is 1 M NaCl.
  • If the same 1 mole is dissolved to make 2 litres of solution, the molarity becomes 0.5 M (because the same amount of solute is now spread through more volume).

In simple words: Molarity tells you how many “chemistry packets” (moles) of a substance are packed into each litre of solution.

TL;DR:
Molarity is called the molar concentration of a solution and is equal to moles of solute divided by litres of solution, with unit mol/L and symbol M.

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