Introduction:
Vapor pressure is defined as the pressure at which the vapor phase of a substance is in equilibrium with its liquid or solid phase. The vapor pressure of a solution is lower than that of the pure solvent due to the presence of solute particles in the solution. In this context, we will discuss the vapor pressure of glucose and pure water.

Factors affecting vapor pressure:
The vapor pressure of a solution depends on several factors, including:

- Temperature
- Nature of the solute and solvent
- Concentration of the solute

Vapor pressure of glucose and pure water:
When glucose is dissolved in water, the vapor pressure of the resulting solution is lower than that of pure water. This is because the presence of glucose molecules in the solution reduces the number of water molecules at the surface of the solution, which in turn reduces the number of water molecules that can escape into the vapor phase. As a result, the vapor pressure of the solution is lower than that of pure water.

Comparison of vapor pressure:
Pure water has a higher vapor pressure than a solution of glucose and water. This is because the presence of glucose molecules reduces the number of water molecules that can escape into the vapor phase, resulting in a lower vapor pressure. Therefore, pure water has a higher vapor pressure than a solution of glucose and water.

Conclusion:
In conclusion, the vapor pressure of a solution of glucose and water is lower than that of pure water. This is due to the presence of glucose molecules in the solution, which reduces the number of water molecules at the surface of the solution that can escape into the vapor phase. Therefore, pure water has a higher vapor pressure than a solution of glucose and water.