The vapour pressure of 30 % w / v , aqueous solution of glucose is ________ mm Hg at 25 ∘ C . [Given: The density of 30 % w / v , aqueous solution of glucose is 1 . 2 g cm – 3 and vapour pressure of pure water is 24 mm Hg .] (Molar mass of glucose is 180 g mol – 1 )

Step-by-step solution

To calculate the vapour pressure of the 30 % (w/v) aqueous solution of glucose, we can use Raoult's law, which states that the vapour pressure of a component in an ideal solution is directly proportional to its mole fraction in the solution. Weight of solution = 100 × 1 . 2 = 120   gm Weight of water = 120 - 30 = 90   gm Now using formula P 0 - P P = moles   of   glucose moles   of   water 24 - P P = 30 180 90 18 = 3 90 24 × 90 - P × 90 = 3   P ⇒ P = 23 .