Molarity Calculator

Calculate molarity, mass concentration, and moles of solute

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Molarity Calculator

Please provide any three values in the fields below to calculate the fourth value in the molarity equation: Molarity = Mass / (Molecular Weight × Volume)

🧪 Molarity Calculation

📊 Results

Molarity
0.8556 M
moles per liter
Mass Concentration
50 g/L
Moles of Solute
1.7112 mol

Calculation Steps

Molarity Formula:
M = mass / molecular weight × volume
Substitution:
M = 100 g / (58.44 g/mol × 2 L) = 0.8556 M

📚 Understanding Molarity

What is Molarity?

Molarity (M) is a measure of the concentration of a solution expressed as the number of moles of solute per liter of solution.

Formula

M = n/V, where M is molarity (mol/L), n is the number of moles of solute (mol), and V is the volume of solution (L).

Applications

Molarity is critical in laboratory experiments, pharmaceutical preparations, and industrial chemical processes.

Measuring Molarity Using Molecular Weight

Often, we may not know the number of moles of solute directly and instead are given the mass of the solute. Given the mass of the solute, we can calculate the number of moles of solute by dividing the mass of the solute by its molecular weight.

The formula to calculate molarity using molecular weight is:

M = mass / (molecular weight × volume)

Where M is the molarity (mol/L), mass is the mass of the solute (g), molecular weight is the molecular weight of the solute (g/mol), and volume is the volume of the solution (L).

Example Calculation

Problem: If you have 10 grams of sodium chloride (NaCl) and dissolve it in water to form a solution of 500 mL (0.5 L). The molecular weight of NaCl is 58.44 g/mol. Find the molarity of the solution.

Solution:

M = 10 g / (58.44 g/mol × 0.5 L) = 0.342 M

Thus, the molarity of the sodium chloride solution is 0.342 M.