wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Define molarity and molality and explain its difference?

Open in App
Solution

Molarity can be defined as the number of moles of a substance (known as the solute) that is dissolved in precisely 1 liter of a solution (solvent and solute combined).
Molarity (M) = moleofsoluteLitreinsolution
Molality can be defined as the number of moles of substance (known as the solute) that is found in a certain mass of solvent given in kg, that it is dissolved in.
Molality(m) = molesofsolute(moles)Massofsolvent(kilogram)
Difference between Molarity and Molality
1) Molarity is concentration of a substance that is calculated as the number of moles of solute that is dissolved in 1 liter of solution while molality is concentration of a substance that is calculated as the number of moles of solute found in 1 kg of solvent.
2) The symbol for molarity is M, while that for molality is m (sometimes written as m or m to distinguish it from mass).
3) The formula for molarity is moles / liter while the formula for molality is moles / kg.
4) Molarity is affected by changes in temperature while molality is unaffected by changes in temperature.
5) Molarity is affected by changes in pressure while molality is unaffected by changes in pressure.
6) Molarity may result in an imprecise and inaccurate concentration, while molality results in an accurate precise measurement of concentration.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Concentration of Solutions
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon