Question

23g of ethyl alcohol is dissolved in 54g of water. calculate molar fraction of ethyl alcohol and water in solution

pls answer me quickly​

Answer 1

Given :

▪ Weight of ethyl alcohol = 23g

▪ Weight of water = 54g

To Find :

▪ Mole fraction of ethyl alcohol.

▪ Mole fraction of water.

$\bigstar\:\underline{\boxed{\bf{\red{Mole\:Fraction:}}}}$

❇ Name : Mole fraction

❇ Symbol : x

❇ Definition : Ratio of number of moles of one component to the total number of moles of all the components.

❇ Effect of temperature : No effect

❇ Formula :

$\bigstar\:\underline{\boxed{\bf{\purple{x_A=\dfrac{n_A}{n_A+n_B}}}}}$

Calculation :

✴ Molecular weight of water = 18g/mol

✴ Molecular weight of ethanol = 46g/mol

↗ Moles of water = 54/18 = 3

↗ Moles of ethanol = 23/46 = 0.5

❍ Mole fraction of water :

$\Rightarrow\sf\:x_{w}=\dfrac{n_w}{n_w+n_e}\\ \\ \Rightarrow\sf\:x_{w}=\dfrac{3}{3+0.5}\\ \\ \Rightarrow\sf\:x_{w}=\dfrac{3}{3.5}\\ \\ \Rightarrow\underline{\boxed{\bf{\blue{x_w=0.86}}}}\:\gray{\bigstar}$

❍ Mole fracrion of ethanol :

$\dashrightarrow\sf\:x_w+x_e=1\\ \\ \dashrightarrow\sf\:0.86+x_e=1\\ \\ \dashrightarrow\sf\:x_e=1-0.86\\ \\ \dashrightarrow\underline{\boxed{\bf{\green{x_e=0.14}}}}\:\orange{\bigstar}$

Answer 2

Given:

• 23g of ethyl alcohol is dissolved in 54g of water

To find:

• Molar fraction of ethyl alcohol & water in Solution

Solution:

★ Formulas of given compounds :

• Ethyl alcohol : C₂H₅OH
• Water : H₂O

★ Concept :

• Mole fraction :Mole fraction of a compound is defined as the ratio of number of moles of element to the total number o moles of the solution

___________________________________

Here , given equation

Mass of C₂H₅OH

C₂ = 2 × (mass of carbon) = 2 × 12 = 24 g

H₅ = 5 × (mass of Hydrogen) = 5 × 1 = 5g

OH = 16 + 1 = 17g

Mass of ethyl = Mass (C₂ + H₅ + OH)

Mass of ethyl = 24 + 5 + 17

Mass of ethyl = 46 g

Mass of water = 2 × 1 + 16 = 18 g

Now, finding number of moles of each element

Firstly , C₂H₅OH

Here , mass of ethyl = 23 grams

We know that

Actual mass of ethyl for one mole = 46

Given mass of ethyl = 23

They differ by 1/2

So , no. of mole of ethyl = 0.5 moles

H₂O

Actual mass = 18

Given mass = 56

The differ by 3.11 ≈ 3

So, no. of moles = 3

Now,

Mole fraction = n(element)/n(total solution)

X(ethyl) = 0.5/0.5 + 3

X(ethyl) = 0.12

x(water) = 3/0.5 + 3

x ( water) = 0.85

Hence, mole fraction of ethyl = 0.12 , mole fraction of water = 0.85