Insulin `(C_2H_(10)O_(5))_n,` is dissolved in a suitable solvent and the osmotic pressure `(pi)` of solutions of various concentrations (g/cc) C is measured at `20^@C.` The slope of the plot of `(pi)` against 'C' is found to be `4.65 xx 10^(-3)`. The molecular weight of insulin is:

Options

A. `4.8 xx 10^(5)`
B. `9 xx 10^(5)`
C. `3 xx 10^(5)`
D. `5.17 xx 10^(6)`

Answer

D

Explanation

`piV=w_B/m_B xx RT , pi =(w_B/V) (RT)/(m_B)`
`pi=C xx (RT)/(m_B) xx 1000 ……..(i)`
where C=concentration in g/cc,
`y=x xx m ……..(ii)`
Comparing eqs. (i) and (ii), Slope `=(RT)/(m_B)= xx 1000`
`m_B=(RT)/("Slope") xx 1000=(0.0821 xx 293 xx 1000)/(4.65 xx 10^(-3))=5.17 xx 10^6`