# What is an expression of molality?

$m$ = moles of $s o l u t e$ $/$ kilogram of $s o l v e n t$
Morality is defined as number of moles of solute dissolved per kilogram of solvent. For example when $58.5 g$ of $N a C l$ is dissolved in one kilogram of water the resulting solution would be one molal or 1m $N a C l$ .