Molar Concentration Calculator
Calculated Molarity:
Understanding Molar Concentration (Molarity)
Molar concentration, commonly referred to as molarity (M), is a measure of the concentration of a chemical species, in particular a solute, in a solution. It is defined as the amount of substance (measured in moles) per unit volume of solution (measured in liters).
Since we often measure substances in grams rather than moles, we must first convert the mass to moles using the substance's molar mass. The expanded formula used by this calculator is:
How to Calculate Molarity: A Step-by-Step Example
Suppose you want to find the molarity of a solution where 116.88 grams of Sodium Chloride (NaCl) is dissolved in 2 Liters of water.
- Step 1: Identify the Mass. Mass = 116.88 g.
- Step 2: Find the Molar Mass. The molar mass of NaCl is approximately 58.44 g/mol.
- Step 3: Calculate Moles. Moles = 116.88 / 58.44 = 2 moles.
- Step 4: Divide by Volume. Molarity = 2 moles / 2 Liters = 1.0 M.
Common Molar Masses for Reference
| Substance | Chemical Formula | Molar Mass (g/mol) |
|---|---|---|
| Sodium Chloride | NaCl | 58.44 |
| Glucose | C6H12O6 | 180.16 |
| Sucrose | C12H22O11 | 342.30 |
| Sodium Hydroxide | NaOH | 39.99 |
Importance in Chemistry
Molarity is the most common unit of concentration used in chemical laboratories. It allows scientists to perform stoichiometric calculations for reactions occurring in solution. By knowing the molarity, one can precisely calculate how much of a reactant is present in a specific volume of liquid, which is essential for titrations and synthesizing new chemical compounds.