The difference is in the denominators.
Molarity (M) - the number of moles of solute divided by the number of liters of solution.
Molality(m) - the number of moles of solute divided by the number of kilograms of solvent.
Molarity or Molality
In dilute solutions... ie closer a solution is to pure water the closer molality and molarity come to equalling each other. This is because the molality uses mass and molarity uses volume, the ratio of these two (mass and volume) is density, and water has the density of 1 therefore the mass and volume are equal to each other. THEREFORE calculating the molarity of water is the same as calculating the molality of water.
The number of moles of solute dissolved in 1 L of a solution would be the molarity. As an example, if you had 2 moles of solute in 1 liter the molarity would be 2M.
if one scientist reports concentrations measured in molality, another scientist elsewhere can exactly replicate the work. This is not possible with molarity. I chose the above answer on my quiz and it was actually incorrect. The correct answer should be - two solutions of the same molality have equivalent ratios of solute to water, but two solutions of the same molarity may not have equivalent ratios.
moles of solute over kg of solvent
through molarity,molality, normality. through molarity,molality, normality.
Molarity or Molality
In dilute solutions... ie closer a solution is to pure water the closer molality and molarity come to equalling each other. This is because the molality uses mass and molarity uses volume, the ratio of these two (mass and volume) is density, and water has the density of 1 therefore the mass and volume are equal to each other. THEREFORE calculating the molarity of water is the same as calculating the molality of water.
The number of moles of solute dissolved in 1 L of a solution would be the molarity. As an example, if you had 2 moles of solute in 1 liter the molarity would be 2M.
"MolaRity" is the correct spelling for mass per amount solution."MolaLity" is the correct spelling for mass per amount solvent.The conversions of molality, b, to and from the molarity , c,for one-solute solutions are:c = ρ.b / [1 + b.M]andb = c / [ρ -c.M]where ρ is the mass density of the solution, b is the molality, and M is the molar mass of the solute.
Both express moles of solute in the numerator.
Molality is used when temperature varies in an exothermic or endothermic reaction because it is not dependent on temperature or pressure. Molality does not depend on tempratute whereas molarity does.
HCl is a strong acid no matter the molarity or molality.
Molarity is a measure of the concentration of a solution, and therefore cannot be said to be just moles.It is in fact moles per litre (mol/L), or molars.
if one scientist reports concentrations measured in molality, another scientist elsewhere can exactly replicate the work. This is not possible with molarity. I chose the above answer on my quiz and it was actually incorrect. The correct answer should be - two solutions of the same molality have equivalent ratios of solute to water, but two solutions of the same molarity may not have equivalent ratios.
Mol is a cocentration unit !
4 mol over 0.800 kg