Question

A solution is prepared by dissolving `1.08 g` of human serum albumin, a protein obtained from blood plasma, in `50 cm^(3)` of aqueous solution. The solution has an osmotic pressure of `5.85 mm Hg` at `298 K`.
a. What is the molar mass of albumin ?
b. What is the height of water column placed in solution ?
`d_((H_(2)O)) =1 g cm^(-3)`

Answer 1

a. The molar massof albumin can be calculated using the following relation
`Mw_(B)=(W_(B)xxRT)/(piV)` ….(i)
Given,`W_(B)=1.08 g`,`R=0.0821 L atm K^(-1) mol^(-1)`
`T=298 K , pi=(5.85)/(760) atm,V=(50)/(1000) = 0.005 L`
Substituting these values in Eq.(i), we get
`Mw_(B)=(1.08xx0.0821xx298)/((5.85//760)xx0.05)=68655 g mol^(-1)`
b. `pi=hdg`
`(5.85)/(760)xx101325=hxx1xx10^(-3)xx9.8`
[1 atm = 101325 Pa]
`:. h=7.958 xx10^(-2) m =7.958 cm`