Question

Why vapour pressure of saline solution is lower than that of pure water?

Answer 1

Answer:

due to presence of salt as impurity in solution salt particles present at the top surface resulting in reduced no of water molecules at the top and hence reduced vapour pressure.

Answer 2

Answer:

In other words, salt water evaporates slower than pure water. Because of this, the vapor pressure of pure water was higher than the vapor pressure of salt water. ... This was so because water molecules in the vapor phase had an equal chance of condensing back into either the pure or salt water in the sealed container.