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How to calculate molarity

Molarity Calculator

The molarity calculator is a useful tool which allows you to calculate the:

  • mass of a compound required to prepare a solution of known volume and concentration
  • volume of solution required to dissolve a compound of known mass to a desired concentration
  • concentration of a solution resulting from a known mass of compound in a specific volume

Calculate now!

*When preparing stock solutions always use the batch-specific molecular weight of the product found on the vial label and MSDS / CoA (available online).


The molarity calculator equation

The molarity calculator is based on the following equation:

Mass (g) = Concentration (mol/L) x Volume (L) x Molecular Weight (g/mol)
An example of a molarity calculation using the molarity calculator

What is the mass of compound required to make a 10 mM stock solution in 10 ml of water given that the molecular weight of the compound is 197.13 g/mol?

  1. Enter 197.13 into the Molecular Weight (MW) box
  2. Enter 10 into the Concentration box and select the correct unit (millimolar)
  3. Enter 10 into the Volume box and select the correct unit (milliliter).
  4. Press calculate
  5. The answer of 19.713 mg appears in the Mass box
Molarity Calculator FAQ

What is a molarity calculator used for?

This molarity calculator is a tool for converting the mass concentration of any solution to molar concentration (or recalculating the grams per ml to moles). You can also calculate the mass of a substance needed to achieve a desired molarity.

What is the abbreviation for molarity?

Molarity has units of , which can be abbreviated as molar or (pronounced "molar" ). The molar concentration of the solute is sometimes abbreviated by putting square brackets around the chemical formula of the solute.

What is the difference between mass and molarity?

Mass is the mass of the solute (substance) in grams and volume is the total volume of the solution in liters. Molarity has many applications. One of them is to calculate the dilution of the solution. The unit of molarity is moles per cubic decimeter. They are labeled mol/dm³ and M (pronounced "molar").

How do you find the molarity of a solution?

(1) mol. = V*M. where V = the volume of solution and M = the molarity. The mass of solute can also be determined when a volume V is delivered by noting that the number of moles is equal to the mass, m, divided by the formula mass, FM.

What is molarity?

Molarity is the number of moles of solute per liter of solution. For example, if you dissolve table salt in water, salt is the solute, and water is the solution. One mole of sodium chloride weighs 58.44 grams. If you dissolve 58.44 grams of NaCl in one liter of water, you have a one molar solution, abbreviated as 1M. It is important to know, that the volume of solution is measured after the solute is dissolved, not before. Also, don’t confuse molarity with molality, which is slightly different!
When you see “1M”, you read that aloud as a “1 molar solution”.

Does anyone have some sort of resource that can explain to me what the actual hell are moles/molar calculations?

A mole can be considered to be a unit of measurement, just slightly harder to convert between.
You know that to go from grams to kilograms you multiply by a thousand, well to go from grams to moles you divide by the relative atomic/formula mass from the periodic table.
A mole, or avagadro's constant is just a number. It is the number of atoms of an element in a particular mass of that element and it was all based on carbon. So, in 12 grams of carbon there are 6x1023 atoms of carbon. In 14 grams of nitrogen there are 6x1023 atoms of nitrogen.
The reason we convert to moles is because one gram of hydrogen doesn't react with one gram of chlorine to make Hydrochloric Acid, but one atom of hydrogen does react with one atom of chlorine to make hydrogen chloride. When we convert to moles we are converting a known mass of an element into a number of atoms so we can use that number to do calculations relating to that reaction.
Typically in the GCSE you use moles to work out the empirical formula of a compound, that is the simplest whole number ratio of atoms of each element in a compound. Moles must be used because it's a ratio of atoms not a ratio of mass.

How to calculate ph from molarity?

How to calculate pH? - step by step solution
Let’s assume that the concentration of hydrogen ions is equal to 0.0001 mol/l.
Calculate pH by using pH to H+ formula:
pH = -log(0.0001) = 4
Now, you can also easily determine pOH and a concentration of hydroxide ions:
pOH = 14 - 4 = 10
[OH-] = 10-10 = 0.0000000001
Of course, you don't have to perform all of these calculations by hand! Choose the option to determine pH with ion concentration in the calculator and type any of these four values! Then, watch it do all the work for you!
Alternatively, you can find a chemical from the lists (of acids or bases). Let's say you want to know how to find the pH of formic acid - HCOOH. Its Ka is 0.00018.
Choose the concentration of the chemical. Let’s assume that it's equal to 0.1 mol/l.
In order to find a concentration of H+ ions you have to...:
Ka = [H+]*[HCOO-]/[HCOOH]
Ka = x2/(c - x), where
c is the molar concentration of the solution
x is equal to molar concentration of H+
For 0.1 M HCOOH:
[H+] = 0.004154
pH = -log([H+]) = -log(0.004154) = 2.38
Now you know how to calculate pH using pH equations. If you find these calculations time-consuming feel free to use our pH calculator. Select your chemical and its concentration and watch it do all the work for you. When you're finished, check out the titration calculator!

What is graphpad molarity calculator?

Graphpad Molarity Calculators. Molarity Calculators (QuickCalcs) is a web application (no installation required) that helps to dilute a stock solution or to calculate molarity from mass and volume, mass from volume and concentration, volume from mass and concentration. Registration not required.

What is protein molarity calculator?

Molarity is the moles of a solute in a liter of solution. The makes the units of Molarity (M), moles/liter. You can calculate Molarity based on information you have about your protein. To understand how to do a protein molarity calculation, let’s begin with important conversions.
1 Dalton (Da) = 1 g/mol, this means that 1 KDa = 1000 g/mol = 1 kg/mol.

How to calculate concentration from molarity?

As mass / volume = molarity * molar mass, then mass / (volume * molar mass) = molarity.So, in order to calculate the concentration of a solution (in molarity), you need to divide moles of solute by total volume.

How to calculate molarity in a titration?

Use the titration formula. If the titrant and analyte have a 1:1 mole ratio, the formula is molarity (M) of the acid x volume (V) of the acid = molarity (M) of the base x volume (V) of the base. (Molarity is the concentration of a solution expressed as the number of moles of solute per litre of solution.)

How to calculate molarity given volume and concentration?

If you have a solution, you multiply the molarity by the volume in litres.
There are two steps:
Multiply the volume by the density to get the mass.
Divide the mass by the molar mass to get the number of moles.

How to calculate molarity of a solution?

The key to calculating molarity is to remember the units of molarity (M): moles per liter.
To calculate molarity:
Find the number of moles of solute dissolved in solution,
Find the volume of solution in liters, and.
Divide moles solute by liters solution.