You would need exactly 50 molecules of glucose.
Answer: The partial pressure of the Kr is 320 mm Hg.
Explanation:
According to Raoult's Law , the partial pressure of each component in the solution is equal to the total pressure multiplied by its mole fraction. It is mathematically expressed as

where,
= partial pressure of component A
= mole fraction of A
= total pressure
mole fraction of Krypton = 

Thus partial pressure of the Kr is 320 mm Hg