Question

Find the molality of the solution of 25 g of I2 in 125 g of ethanol, C2H5OH

Answer 1

Answer : The molality of the solution is, 0.788 mole/Kg

Solution : Given,

Mass of solute,
`I_2` = 25 g

Mass of solvent,
`C_2H_5OH` = 125 g

Molar mass of solute,
`I_2` = 253.8 g/mole

Molality : It is defined as the number of moles of solute present in one kilogram of solvent.

Formula used :

`Molality=\frac{\text{Mass of solute}* 1000}{\text{Molar mass of solute}* \text{Mass of solvent}}`

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

`Molality=(25g* 1000)/(253.8g/mole* 125g)=0.788mole/Kg`

Therefore, the molality of the solution is, 0.788 mole/Kg