Molarity Calculator

What is Molarity?

Molarity is a measure of the concentration of a solution, defined as the number of moles of solute per liter of solution. It is one of the most common ways to express solution concentration in chemistry. Molarity is typically denoted by the symbol M or mol/L.

How to Calculate Molarity

To calculate the molarity of a solution, follow these steps:

1. Determine the number of moles of solute
2. Measure the volume of the solution in liters
3. Divide the number of moles of solute by the volume of the solution

Formula

The formula for calculating molarity is:

\[ M = \frac{n}{V} \]

Where:

• \(M\) is the molarity in mol/L or M
• \(n\) is the number of moles of solute
• \(V\) is the volume of the solution in liters

Calculation Steps

Let's calculate the molarity of a solution:

• Mass of solute = 5.85 g
• Molecular weight of solute = 58.5 g/mol
• Volume of solution = 0.5 L

1. Calculate the number of moles of solute: \[ n = \frac{\text{mass}}{\text{molecular weight}} = \frac{5.85 \text{ g}}{58.5 \text{ g/mol}} = 0.1 \text{ mol} \]
2. Apply the molarity formula: \[ M = \frac{n}{V} = \frac{0.1 \text{ mol}}{0.5 \text{ L}} = 0.2 \text{ M} \]

Example and Visual Representation

Let's visualize the molarity calculation for our solution:

This visual representation shows:

• A solution containing 5.85 g (0.1 mol) of solute
• The volume of the solution (0.5 L)
• The calculated molarity of 0.2 M

This example demonstrates how we can determine the molarity of a solution using the mass of solute, its molecular weight, and the volume of the solution. Molarity is a crucial concept in chemistry, used in various applications such as preparing solutions, calculating reaction rates, and determining equilibrium constants.