Question

"1. The mole fraction of a solute in a solution is 0.2
and molality of this solution is equal to its
molarity. Ratio of molar mass of solute to solvent is
2 and density of solution is p g/mL, then value of 10p
is if molarity is 5
M​

Answer 1

The mole fraction of a solute in a solution is 0.2 and molality of this solution is equal to molarity. the ratio of molarity of solute to solvent is 2 and density of solution is P g/mL.

The value of 10p is if the molarity is 5 M.

what is molarity and molality ?

molarity : it is just a way to express the concentration of a solution. it is defined as the no of moles of solute in a litre of solution.

molality : it is an another way to express the concentration of a solution. it is defined as the no of moles of solute in a kilogram of solution.

here, mole fraction of solute  = 0.2

so the mole fraction of solvent = 1 - 0.2 = 0.8

molarity  = molality  = 5 M

we know, molality = $\frac{\text{mole fraction of solute}\times1000}{\text{mole fraction of solvent}\times M_A}$ , where $M_A$ is molar mass of solvent.

⇒ 5 = $\frac{0.2\times1000}{0.8\times M_A}$

⇒ $M_A=50$

as it has given that, molar mass of solute = 2 × molar mass of solvent

so, $M_B$  = 2 × 50 = 100

we know the relation between molarity , molarity , density and molar mass of solute is given as

$\text{molality}=\frac{1000\times M}{1000\rho-MM_B}$

⇒ 5 = $\frac{1000\times5}{1000\times p-5\times100}$

⇒ p = 1.5

⇒ 10p = 15

therefore the value of 10p is 15

Answer 2

Answer:

can u give the derivation of the formulas