# What is the relation between molarity and molality? [closed]

Is the following equation correct:

$$m = \frac{1000 \times M}{M \times M_b - 1000 \times d},$$

where $M$ - molarity, $m$ - molality, $d$ -density of solution, $M_b$ - molar mass of solute?

## closed as unclear what you're asking by Pritt Balagopal, airhuff, Todd Minehardt, M.A.R., paracetamolJul 11 '17 at 14:39

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• You need to mention the units you're using for density. Is it $\pu{g/ml}$, or $\pu{g/l}$ or $\pu{kg/m^3}$? – Pritt Balagopal Jul 11 '17 at 4:39

$$m = \frac{M}{\rho - (M \times wt. of solute)}$$
$m=$molality
$M=$Molarity
$\rho=$density