Question

4.6 gm of methyl alcohol is dissolved in 25.2 gm of water calculate percentage by mass of methyl alchohol & mole fraction of methyl alcohol and water​

Answer 1

Answer :-

• Mass percentage of methanol = 15.44 %

• Mole fraction of methanol = 0.09

• Mole fraction of water = 0.91

Explanation :-

We have :-

→ Mass of methyl alcohol = 4.6 g

→ Mass of water = 25.2 g

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Firstly, let's calcualte the mass percentage of methyl alcohol in the solution .

= 4.6/(4.6 + 25.2) × 100

= 4.6/29.8 × 100

= 460/29.8

= 15.44 %

Moles of methanol (CH₃OH) :-

= 4.6/32

= 0.143

Moles of water (H₂O) :-

= 25.2/18

= 1.4

Mole fraction of methanol :-

= Moles of methanol/Total moles

= 0.143/(0.143 + 1.4)

= 0.143/1.543

= 0.09

Mole fraction of water :-

= Moles of water/Total moles

= 1.4/(0.143 + 1.4)

= 1.4/1.543

= 0.91

Answer 2

Given :

Mass of Methyl alcohol = 4.6g

Mass of Water = 25.2g

To Find :

1. Mass Percentage of Methanol
2. Mole Fraction of Methanol
3. Mole Fraction of Water

Solution :

1. Calculating The Mass percentage of Methyl Alcohol in the Solution :

⇒ [4.6/(4.6 + 25.2)] x 100

⇒ (4.6/29.8) x 100

⇒ 0.1544 x 100

⇒ 15.44 %

then,

➻ Moles of Methanol (CH₃OH) :

=> 4.6/32

=> 0.143

➻ Moles of Water (H₂O) :

=> 25.2/18

=> 1.4

2. Calculating The Mole Fraction of Methanol :

⇒ 0.143/(0.143 + 1.4)

⇒ 0.143/1.543

⇒ 0.09

3. Calculating The Mole Fraction of Water :

⇒ 1.4/(0.143 + 1.4)

⇒ 1.4/1.543

⇒ 0.91

FINAL ANSWER :

1. Mass Percentage of Methanol = 15.44%

2. Mole Fraction of Methanol = 0.09

3. Mole Fraction of Water = 0.91

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FORMULAS USED :

Mass Percentage of a Solute in a Solution is calculated by :

(Mass of Solute/Total Mass of Solution) x 100

Mole Fraction of a Substance is calculated by :

No.of.Moles of a Substance/Total Moles present in the Solution