Question

CALCULATE THE MOLALITY OF ETHANOL SOLUTION IN WHICH THE MOLE FRACTION OF WATER IS 0.88 .

Answer 1

Answer:

Answer:- 407.4m.

Explaination:

Molality is moles of solute per kg of solvent. For the given problem, the solute is ethanol and solvent is water. The mole fraction of ethanol is given as 0.88.

We know that, the sum of mole fractions is 1. So, if the mole fraction of ethanol is 0.88 then mole fraction of water would be = 1 - 0.88 = 0.12

It's simply like we have 0.88 moles of ethanol and 0.12 moles of water. Since. mole fraction is moles divided by total moles.

For example, mole fraction of ethanol =

Let's convert 0.12 moles of water to g and then kg:

= 0.00216 kg

So, the molality of the solution = 407.4m

So, the molality of the solution is 407.4 m.

Answer 2

Answer:

Mole fraction of water, $XH_{2} O$=0.88

Mole fraction of ethanol,$XC_{2} H_{5} OH$=1-0.88=0.12

$XC_{2} H_{5} OH=n_{2} /n_{1} +n_{2} ---(1)$

n2=number of moles of ethanol

n1=number of moles of water

$n_{1} =1000/18=55.5moles$

substitute the values of n1 in equation 1

$n_{2} /55.5+n_{2} =0.12$

$n_{2} =7.57moles$

molarity of ethanol$(C_{2} H_{5} OH)=7.57m$