Molarity Calculator

An online molarity calculator helps you to calculate molarity, volume, concentration and mass of a concentrated or dilute solution. You can get required answers in many units for a specific term by using this tool.

Here, we will discuss the comprehensive concept of molarity in detail.

What is Molarity?

In the subject of chemistry, molarity is defined as:

“ a term that refers to the concentration of moles present in a litre of solution.”

Molarity Formula:

The basic chemical formula to determine the molarity of a given solution is given as follows:

Molarity = number of moles of a solute / litres of a solution

M = n / V

Where;
M = molarity of the solution;
n = number of moles of solute;
V = volume of the solution.

Also, our online concentration calculator is the best way to find the molarity (concentration) of any solution.

Units of Molarity:

In chemistry, the units of molarity are mol/L or mol⋅dm−3.

To calculate molarity, we must have a proper idea to determine the following quantities:

Moles of a Solute:

The concentration of solute particles in a given volume of solution is known as moles of a solute.

The number of moles of solute = mass of solute / molar mass of solute

Molecular Mass of Solute:

The sum of all the atomic masses of each atom present in a molecule is termed as the molecular mass of that molecule.

Mass of Solute:

You can determine the mass of the solute by using the formula below;

Mass of Solute = Concentration of Solute (mM) * Volume of the Solution (mL)

Volume of a Solution:

The following formula helps us to find the exact volume of any solution:

C = m/V
or;
V = m /C

where;
V = volume of solution;
m = moles of solute;
C = concentration of the solution

The free online molarity calculator calculates all parameters mentioned above to generate accurate results instantly.

Dilution of Stock Solution:

A stock solution is a concentrated solution. Addition of the solvent in the solution to make it more dilute or less concentrated is known as dilution of stock solution.

Dilution of stock solution s given as:

C1V1 = C2V2

Where;
V1 = Volume of stock solution required to make the new solution;
C1 = Concentration of stock solution;
V2 = Final volume of new solution.
C2= desired concentration

How to Calculate Molarity (Step-by-Step)?

Let us solve a couple of examples to calculate the molarity of any solution.

Example # 01:

A solution is prepared by dissolving 1.2 g of NaCl in Water. What is the molarity of the solution when the volume of the solutio is 23.4 mL.

Solution:

Given mass of NaCl = 1.2 g

Molecular Mass of NaCl = Atomic mass of Na + Atomic mass of Cl

= 23 + 35.5

= 58.5 g / mol

Molecular mass of water = Atomic mass of hydrogen + Atomic mass of oxygen

= 2 (1) + 16

=18 g / mol

Now, the number of moles of NaCl is given as follows:

Number of Moles = Given mass of NaCl / Molar Mass of NaCl

=1.2 / 58.5

= 0.0205 mol

Expressing the volume in terms of litres;

Volume = 23.4 / 1000

Volume = 0.0234 L

Now, calculating molarity of the solution as follows;

Molarity = No. of Moles of Solute / Volume of Solution in Litres

Molarity = 0.0205 / 0.0234

Molarity = 0.8760 M

You can also verify the results by putting all these values in a molar calculator.

Example # 02:

Determine the mass of the KCl with given volume of the solution to be 0.056 and molarity as 1.6 M

Solution:

Molecular Mass of KCl = Atomic Mass of K + Atomic Mass of Cl

= 39.1 + 35.5

= 74.6 g / mol

Moles of KCl = Given Mass / Molar Mass
or;
Mass of KCl = Moles of KCl * Molar Mass

The number of moles can be determined by using the Molarity formula:

Molarity = No. of Moles of Solute / Volume of Solution in Litres
or;
no. of moles = Molarity * Volume of Solution in Litres

= 1.6 * 0.056

= 0.0896 mol

Now the mass of KCl is given as follows:

Mass of KCl = Moles of KCl * Molar Mass

= 0.0896 * 74.6

= 6.684g

The molarity calculator calculates the same values in different units.

Example # 03:

You are given a solution having fixed volume of 0.9876 and molarity of 3.4M. The desired molarity of the solution that is required is 2.41 M. Find volume of the new solution after desired molarity is achieved?

Solution:

As we know that;

Volume of the new solution is calculated as:

C1V1 = C2V2

V1 = C2 * V2 / C1

V1 =2.41 * 0.9876 / 3.4

V1 = 0.7L

Finally, you encounter how to find molar concentration step-by-step manually, and if your preference indulges with instant calculations, then free molar calculator is best.

How Molarity Calculator Works?

Exact value of molarity in different units can easily be calculated by using online molar concentration calculator.

Input:

You could calculate either:

• Mass from Volume & Concentration
• Volume from Mass & Concentration
• Molarity from Mass & Volume
• Dilute a Stock Solution
• After you select any one of the above parameters, enter the values.
• Click ‘Calculate’.

Output:

Calculated result depends upon the input you entered and can either be:

• Molarity of a solution
• Volume of solution
• Mass of the solution
• Desired volume of the diluted stock solution

FAQ’s:

What is meant by Molality?

The number of moles of a solute per kilogram of a given solvent is called the molality of that particular solution.

Does change in volume affects the molarity of a solution?

With the same amount of solute, an increase in volume causes a decrease in molarity of the solution and vice versa.

What are the units of Molality?

The SI unit of molality is mol/kg.

What is the Molarity of pure water?

The molarity of pure water is 55.55M.

Conclusion:

Wherever you’re going to deal with different solutions, it is crucial to know about the exact molarity figures to reduce uncertainty. Molarity always introduces you with the nature of the solution (whether it is concentrated or dilute). Online molarity calculator exactly figure out the molarity of every type of the solution.

References:

From the source of wikipedia:Molar concentration, Formality or analytical concentration.

From the source of khan academy: Introduction: Mixtures and solutions, Molar concentration, Calculating the molar concentration of a solute, Making a solution with a specific concentration.

From the source of lumen learning: Calculating Molarity, Calculating Molarity Given Moles and Volume, Calculating Moles Given Molarity, Calculating Volume Given Molarity and Moles, Dilution.