Question

If 1.1g of nitrobenzene are added to 10.0 g of naphthalene, show the correct work to find the molality of the solution? (given: molar mass of nitrobenzene = 123.06g/mole)

Answer 1

Answer: Molality of solution is 0.89 mole/kg

Step-by-step explanation:

Molality of a solution is defined as the number of moles of solute dissolved per kg of the solvent.

`Molarity=(n)/(W_s)`

where,

n = moles of solute

`W_s` = weight of solvent in kg

moles of nitrobenzene (solute) =
`\frac{\text {given mass}}{\text {Molar Mas}}=(1.1)/(123.06g/mol)=0.0089`

mass of napthalene (solvent )= 10.0 g = 0.0100 kg

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

`Molality=(0.0089)/(0.0100kg)=0.89mole/kg`

Therefore, the molality of solution is 0.89 mole/kg