At 300 K, a one litre solution of sucrose (molecular weight : 342 ) was prepared by dissolving 40 g of sucrose. What is the approximate osmotic pressure (in kPa) of solution at the same temperature ?
`(R = 8.314 xx 10^6 cm^3 Pa K^(-1) mol^(-1))`

Options

A. 292
B. 500
C. 292000
D. 600

Answer

A

Explanation

Osmotic pressure `(pi)=nRT`
where, I = vant-Hoff's factor = 1 for sucrose
n = number of moles `=("weight in gram")/("molecular weight")`
`=(40)/(342)` for sucrose
R = gas constant `=8.314xx10^(6)" cm"^(3)"Pa K"^(-1)"mol"^(-1)`
T = temperature = 300 K
Substituting in formula of osmotic pressure, we get
`pi=1xx(40)/(342)xx8.314xx10^(6)xx300`
`=291" kPa`