Question

an aqua solution of glucose is made by dissolving 10 gram of glucose in 90 g and water at 303 Kelvin. if the vapour pressure of pure water at 303 Kelvin be 32.8 mm hg. what would be the vapour pressure of solution?? please answer this question ​

Answer 1

Here, molar mass of glucose (C6H12O6 ) = 180 gm/mol

Molar mass of water = 18 gm/mol

So, moles of sugar solute = given mass/ molar mass = 10/180 = 0.05 mol

Moles of solvent water = 90/18 = 5 mole

So, mole fraction of solvent = moles of water / moles of solution = 5/ 5+0.5 = 5/5.05 = 0.99

Now, we have vapor pressure of solution,

Psolution = Xsolvent x P0solvent

Where, P0solvent = pure vapor pressure of solvent (water) = 32.8mm hg (as given)

and Xsolvent = mole fraction of solvent (water)

So, Psolution = 0.99 x 32.8 =32.47 mmhg

Answer 2

an aqua solution of glucose is made by dissolving 10 gram of glucose in 90 g and water at 303 Kelvin and the vapour pressure of pure water at 303 Kelvin is 32.8 mm hg.