About us | Feedback

Molar concentration (molarity) definition

Concentration calculation

CASC concentration calculator

operating systems:
XP, Vista, 7, 8, 10

single user license price:
€49.95 - approximately $65

Buy Now!

By clicking Buy Now! you will continue to the FastSpring checkout page where payment will be taken, and your order fulfilled by FastSpring, our trusted reseller, and Merchant of Record.

download 30-day free trial!
30-day money back guarantee!

Concentration lectures » molar concentration

Molarity - or more correctly molar concentration, often denoted by M - is defined as

molar concentration definition, eq. 6.16.1

and expressed in [mole/L] units. This is the most often used concentration unit, molar concentrations are often measured with highest precision and for most analytical applications this is the preferred way of expressing concentration as it makes stoichiometric calculations much easier.

The only drawback is that molar concentration depends on the temperature - when the solution gets warm it's volume in most cases increase and molar concentration goes down. 5 deg C temperature difference leads to concentration change in 0.1% range - so it can be a source of error of the same range as volume readings on the precise burette.

In old books and papers you may sometimes find concentration expressed as M/500 - which means 1 mol per 500 litres of solution (thus M/500 means 0.002 mol/L).

For example of molarity conversion see percentage to molarity section.


Chemical calculator software for pH calculation, concentration conversion solution preparation and chemical equation balancing chemical calculator