Question

ऐसा कौन सा चीज है जो रिवर्सिबल है पर केमिकल है

Answer 1

If you keep water in the freezer for some time, it transforms into ice. But as soon as you take it out of the freezer, it turns into water again. This is a reversible change. Similarly, if you boil water, it evaporates and becomes water vapour. When you cool this vapour down, it turns back to water.

Answer 2

Water is that substance which follows reversible change as well as it is a chemical.
Reversible change is of water to ice and again from ice to water.