To calculate the vapour pressure of a 10% glucose solution, we can use Raoult's law, which states that the vapour pressure of a solution is equal to the mole fraction of the solvent multiplied by the vapour pressure of the pure solvent.

The mole fraction of water in a 10% glucose solution can be calculated as follows:

Mole fraction of water = (moles of water) / (total moles of solution)

Assuming we have 100 grams of solution, we can calculate the moles of water and glucose as follows:

Moles of water = (100 - 10) / 18 = 5 moles

Moles of glucose = 10 / 180 = 0.0556 moles

Therefore, the mole fraction of water is:

Mole fraction of water = 5 moles / (5 + 0.0556) moles = 0.988

Now, we can use Raoult's law to calculate the vapour pressure of the solution:

Vapour pressure of solution = Mole fraction of water × Vapour pressure of pure water

Vapour pressure of solution = 0.988 × 30 mm = 29.64 mm

Therefore, the vapour pressure of a 10% glucose solution is 29.64 mm.