Question

0.
Calculate the mole percentage of CH,OH and H,O respectively in 60% (by mass) aqueous solution of CH OH
(1) 45.8, 54.2
(2) 54.2, 45.8
(3) 50, 50
(4) 60.40​

Answer 1

Answer:

Given,

60% by mass solution of CH

3

OH. That means in 100gm solution

60gm CH

3

OH is dissolved in 40gm H

2

O

∴ Molar mass of CH

3

OH=32g/mol

Molar mass of H

2

O=18g/mol

⇒ No. of moles of CH

3

OH=

32g/mol

60gm

=1.875 mol ..........(1)

No. of moles of H

2

O=

18gm/mol

40gm

=2.222 mol ..........(2)

Total no. of moles=1.875+2.222=4.097 moles ..........(3)

⇒ Mole percentage=

Total no. of moles

Moles of compound

×100

Mole % of CH

3

OH=

4.097

1.875

×100

=45.8% (From 1 & 3)

Mole % of H

2

O=

4.097

2.222

×100

=54.23% (from 2,3)

Hence, the correct option is 4