Question

Osmotic pressure of a solution containing 5g of

protein in 500 ml of solution at 300 K is 1.66 bar.

This protein contain 48% carbon. What is number

of carbon atoms present in one molecule of protein :-

(1) 2
(2) 4
(3) 6
(4) 8​

Answer 1

Given:

w = 5g

V = 500 ml

T = 300 K

Π = 1.66 bar

% of carbon in the protein = 48%

To Find:

The no of carbon atoms present in one molecule of protein.

Calculation:

- We know that:

Π = C×R×T

⇒ Π = {(w × 1000)/(M.wt × V)} × R × T

⇒ 1.66 =  {(5 × 1000)/(M.wt × 500)} × 0.0831 × 300

⇒ M.wt = (10 × 24.93)/1.66

⇒ M.wt = 249.3/1.66

⇒ M.wt = 150.18 gm

- The mass of carbon in 1 molecule = 48 % of it

⇒ m = (48/100) × 150.18

⇒ m = 72.087 gm

- The no of carbon atoms = 72.087 / 12

⇒ n = 6

- So, the correct answer is option (3) 6.