Question

solution is 2.41 molal toluene (C 7H 8, 92 g/mol) in benzene (C 6H 6, 78 g/mol); i.e. consider toluene the solute, benzene the solvent. What is the molarity? The density of the solution is 0.876 g/cm 3.

Answer 1

Answer : The molarity of solution is, 1.73 mole/L

Explanation :

The relation between the molarity, molality and the density of the solution is,

where,

$d=M[\frac{1}{m}+\frac{M_b}{1000}]$

d = density of solution  = $0.876g/cm^3=0.876g/mL$

m = molality of solution  = 2.41 mol/kg

M = molarity of solution  = ?

$M_b$ = molar mass of solute (toluene) = 92 g/mole

Now put all the given values in the above formula, we get  the molality of the solution.

$0.876g/ml=M\times [\frac{1}{2.41mol/kg}+\frac{92g/mole}{1000}]$

$M=1.73mol/L$

Therefore, the molarity of solution is, 1.73 mole/L