Question

Why is water not used as a barometric liquid?

• A. The density of water is greater than all other liquids.
• B. The density of water is low.
• C. The vapor pressure of water is negligible.
• D. Water gives a correct reading.

Answer 1

The correct option is B

The density of water is low.

There are some disadvantages of using water as a barometric liquid. The density of water is low which is equal to ${10}^{3}kg{m}^{-3}$, so nearly 10.4 m height of water column is needed to balance the atmospheric pressure. Water is highly inconvenient to take a tube of height 10.4 m for a barometer. The vapor pressure of water is high so its vapors in the vacuum space will make the reading inaccurate.