Percentage Concentration to Molarity Calculator
This online percentage concentration to molarity calculator is used in chemistry to convert between two different ways of expressing the concentration of a solution.
Percentage concentration typically refers to the mass of solute per 100 units of solution, while molarity is defined as the number of moles of solute per liter of solution.
The calculator takes into account factors such as the molecular weight of the solute and the density of the solution to perform accurate conversions.
Percent Concentration to Molarity Calculation Formula
The formula to convert percent concentration to molarity involves several steps and considerations. The general formula is:
Molarity (M) = (Percent Concentration × Density of Solution) / (Molecular Weight of Solute × 0.1)
Where:
- Percent Concentration is expressed as a percentage (%)
- Density of Solution is in g/mL
- Molecular Weight of Solute is in g/mol
- 0.1 is a conversion factor to account for the percentage
More Calculator:
How do you convert percentage concentration to molarity?
To convert percentage concentration to molarity, follow these steps:
- Determine the percent concentration of the solution.
- Measure or find the density of the solution in g/mL.
- Identify the molecular weight of the solute in g/mol.
- Apply the formula: Molarity = (Percent Concentration × Density) / (Molecular Weight × 0.1)
- Calculate the result to obtain the molarity in mol/L.
For example, to convert a 5% NaCl solution with a density of 1.03 g/mL to molarity:
- Percent Concentration = 5%
- Density = 1.03 g/mL
- Molecular Weight of NaCl = 58.44 g/mol
- Molarity = (5 × 1.03) / (58.44 × 0.1) = 0.882 M
What is the formula for percent concentration?
The formula for percent concentration depends on whether you’re calculating mass percent or volume percent. Here are both formulas:
Mass Percent Concentration:
Mass Percent = (Mass of Solute / Mass of Solution) × 100%
Volume Percent Concentration:
Volume Percent = (Volume of Solute / Volume of Solution) × 100%
In most cases, when dealing with solid solutes dissolved in liquid solvents, mass percent is used.
What is the formula for Molarity?
The formula for molarity (M) is:
Molarity (M) = Moles of Solute / Liters of Solution
This can also be expressed as:
Molarity (M) = (Mass of Solute / Molecular Weight of Solute) / Volume of Solution in Liters
Molarity is always expressed in units of mol/L or M.
What is 5% concentration?
A 5% concentration means that there are 5 grams of solute dissolved in 100 grams of solution. In other words, 5% of the total mass of the solution is the solute, while the remaining 95% is the solvent.
For example, a 5% salt solution contains 5 grams of salt dissolved in enough water to make 100 grams of solution. It’s important to note that this is a mass-to-mass ratio, not a mass-to-volume ratio.
How to calculate molarity from percentage purity?
To calculate molarity from percentage purity, you need additional information such as the density of the solution and the molecular weight of the solute. Here’s the process:
- Convert percentage purity to decimal form (e.g., 98% = 0.98)
- Multiply the density of the solution by the purity decimal to get grams of pure solute per mL
- Divide by the molecular weight of the solute to get moles of solute per mL
- Multiply by 1000 to convert to moles per liter (molarity)
Formula:
Molarity = (Density × Purity × 1000) / Molecular Weight
Where:
- Density is in g/mL
- Purity is expressed as a decimal
- Molecular Weight is in g/mol
How to find molarity from concentration?
If the concentration is given as a mass percentage, you can use the following steps:
- Convert the percentage to a decimal (e.g., 5% = 0.05)
- Multiply the decimal by the solution density to get grams of solute per mL
- Divide by the molecular weight of the solute to get moles per mL
- Multiply by 1000 to convert to moles per liter (molarity)
Formula:
Molarity = (Concentration × Density × 1000) / Molecular Weight
Where:
- Concentration is expressed as a decimal
- Density is in g/mL
- Molecular Weight is in g/mol
Percentage Concentration to Molarity Conversion Table
We’ll use different concentrations of sodium chloride (NaCl) solutions as our examples.
Given:
- Molecular Weight of NaCl = 58.44 g/mol
- Density of solutions varies slightly with concentration
| Percentage Concentration | Density (g/mL) | Calculation | Molarity (M) |
|---|---|---|---|
| 1% NaCl | 1.0053 | (1 × 1.0053) / (58.44 × 0.1) | 0.172 |
| 5% NaCl | 1.0314 | (5 × 1.0314) / (58.44 × 0.1) | 0.883 |
| 10% NaCl | 1.0707 | (10 × 1.0707) / (58.44 × 0.1) | 1.832 |
| 15% NaCl | 1.1091 | (15 × 1.1091) / (58.44 × 0.1) | 2.846 |
| 20% NaCl | 1.1478 | (20 × 1.1478) / (58.44 × 0.1) | 3.929 |
