The figure shows a simple barometer, which is essentially a U-tube with one end leading to a reservoir whose pressure is desired and the other end open to the atmosphere.
The liquid in the tube is water, with a density of ρ = 1.0 g/cm3. The height of water in the reservoir column is h1. The height of water in the open column is h2. What would happen to the height difference h2 – h1 if the water were replaced by salt water with a density 1.2 g/cm3?