Insulin `(C_(2)H_(10)O_(5))_(n)` is dissolved in a suitable solvent and the osmotic pressure `(pi)` of solutions of various concentrations `(g//cm^(3))C` is measured at `20^(@)C`. The slope of a 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 10^5`

Answer

D

Explanation

`piV=w_B/m_BxxRT=pi=(w_B/V)(RT)/m_B`
`pi=cxx(RT)/m_Bxx1000" "(i)`
where C = concentration in g/cc,
Comparing eqs. (i) and (ii), ...(ii)
`"Slope"=(RT)/m_Bxx1000=m_B=(RT)/"Slope"xx1000`
`(0.0821xx293xx1000)/(4.65xx10^(-3))=5.17xx10^6J`