Question

Mole fraction of urea in its aqueous solution is 0.2 then molality of the solution will be

Answer 1

⤵⤵⤵HERE IS UR ANSWER ⤵⤵⤵

Mole fraction of glucose= 0.2

Molefraction of solution = 1

So, mole fraction of water= 1-0.2

= 0.8

Molality = moles of solute/ kg solvent

Molar mass H2O = 18 g/kg

Mass of H2O = (0.8×18)/1000

=0.014 kg

Molality = 0.2 / 0.014

= 14 M

Answer 2

Answer:

The solution's molality measured is $13.88molal$.

Explanation:

Data given,

The mole fraction of urea, $x_{A}$ = $0.2$

The solution's molality =?

As we know,

• Mole fraction of solute + mole fraction of solvent = 1
• $x_{A} + x_{B} =1$
• $0.2 + x_{B} =1$
• $x_{B} = 0.8$

Thus, the mole fraction of solvent ( water ), $x_{B}$ = $0.8$

Also, the water's molar mass, $M_{B}$ = $18g/mol$

Now, the molality can be calculated by the equation given below:

• Molality = $\frac{x_{A}\times1000 }{x_{B}\times M_{B} }$
• Molality = $\frac{0.2\times1000 }{0.8\times 18 }$
• Molality = $13.88molal$

Hence, the solution's molality = $13.88 molal$.