Question

Explain why:

Mercury loses its meniscus in contact with ozone.

Answer 1

This is due to the formation of mercurous oxide (Hg₂O) which dissolves in mercury.

Answer 2

1. Ozone oxidises mercury to form mercurous oxide (Hg₂O).
2. The formed Hg₂O dissolves in mercury metal.
3. This causes mercury to lose its meniscus.
4. Mercury then sticks to the glass surface.
5. This phenomenon is called tailing of mercury.