A solution of crab hemocyanin, a pigmented protein extracted from crabs,was prepared by dissolving 0.750 g in 125`"cm"^(3)` of an aqueous medium . At `4^(@)"C"` an osmotic pressure rise of 2.6 mm of the solution was observed. The solution had a density of 1.00`"g"//"m"^(3)`. Determine the molecular weight of the protein.

Answer

`5.4xx10^(5)"g/mol"`

Explanation

Solute-B, Water-A
`"h"_("Hg")"P"_("Hg")"g"=hxx"P"xx"g"`
`"h"_("Hg")=("h"_("solution")xx"P"_("solution"))/("P"_("Hg"))=(2.6xx1)/(13.6)"mm of Hg"`
`pi=(2.6)/(13.6xx760)"atm"`
`"m"_("B")=("W"_("B")"RT")/(pixx"V"_("sol")"(L)")=(0.75xx0.082xx227)/((2.6)/(13.6xx760)xx(125)/(100))=(0.75xx0.082xx277xx13.6xx760xx1000)/(2.6xx125)`
`=5.4xx10^(5)"gm mol"^(-1)`