10 g of solute A and 20gm of solute B are both dissolved in 500ml water. The solution has the same osmotic pressure as 6.67 gm of A and 30 gm of B dissolved in the same amount of water at the same temperature. What is the ratio of molar masses of A and B?

Answer

`M_(A)//M_(B)=0.33`

Explanation

`(("W"_("A"))/("m"_("A"))+("W"_("B"))/("m"_("B")))("RT")/("V")=(("W"_("A")^(1))/("m"_("A"))+("W"_("B")^(1))/("m"_("B")))("RT")/("V")`
`(10)/("m"_("A"))+(20)/("m"_("B"))=(6.67)/("m"_("A"))+(30)/("m"_("B"))`
`(3.33)/("m"_("A")=(10)/("m"_(B"))`
`("M"_("A"))/("M"_("B"))=(3.33)/(10)`
`("M"_("A"))/("M"_("B"))=0.33`