Question

The osmotic pressure of blood is 7.65 atm at 27°C. How much glucose should be used per litre to prepare an intravenous injection that has the same osmotic pressure as blood?

Answer 1

Given: Osmotic pressure, π = 7.65 atm

Temperature, T = 27°C = 300 K

Gas constant, R = 0.0821 L atm mol⁻¹ K⁻¹

Molar mass of glucose, M = 180 g/mol

`C = pi/(RT)`

= `7.65/(0.0821 xx 300)`

= 0.3107 mol/L

Mass of glucose = C × M

= 0.3107 × 180

= 55.93 g/L