A $4.0%$ by mass aqueous solution of sucrose (molar mass $342 g mo l^{- 1}$ , non-electrolyte) has density $1.014 g m L^{- 1}$ . Calculate its osmotic pressure at $300 K$ in $atm$ , to two decimal places ( $R = 0.0821 L atm mo l^{- 1} K^{- 1}$ ).

Numerical answer type, answer in atm, tolerance 0.02.

Answer: 2.92 atm

Take

100 g

of solution:

4.0/342 = 0.01170 mol

sucrose; volume

= 100/1.014 = 98.62 mL = 0.09862 L

C = 0.1186 mol L^{- 1}

and

π = CRT = 0.1186 \times 0.0821 \times 300 = 2.921 atm