ANS:D - both (b) and (c)

Humidity (b): Humidity refers to the moisture content in the air, and it does not directly impact the boiling point diagram. The boiling point diagram focuses on the relationship between the boiling points of a solvent at different concentrations of a solute. This relationship is primarily governed by the colligative properties of the solution, such as boiling point elevation. Humidity levels in the ambient air do not influence the concentration of solute in the solution or its colligative properties. Therefore, changes in humidity do not affect the boiling point diagram.

1. Temperature (c): Temperature can certainly affect the boiling point of a solvent. However, the boiling point diagram typically depicts the relationship between boiling points and solute concentration at specific temperatures. The temperatures at which the boiling point diagram is constructed are typically controlled and fixed during experimentation or calculation. Therefore, variations in ambient temperature do not directly impact the boiling point diagram since it focuses on the concentration-dependent changes in boiling point at specific, controlled temperatures.

In summary, while changes in ambient humidity and temperature can affect the boiling point of a solvent, they do not directly influence the boiling point diagram because it is constructed based on controlled conditions of temperature and solute concentration. The boiling point diagram primarily illustrates the effect of solute concentration on the boiling point of a solvent in a solution, irrespective of ambient humidity and temperature fluctuations.