Question

Addition of water to salt or sand is a reversible change whereas to cement is an irreversible change .Justify​

Answer 1

Answer:

Mixing cement with water is an irreversible change because we cannot get back the original cement even after boiling it.

Answer 2

Adding water to cement is an irreversible change.

Explanation:

• Adding water to salt is a reversible change.  
• When we heat the solution, we can see the salt left behind and the whole water evaporates.
• Adding water to soil is a reversible change.
• After mixing soil into the water we can separate it easily.
• But when we add water to the cement it is an irreversible change.
• This Is because we cannot separate the solution and cannot get it into its original form even after heating it.
• Hence, it is a chemical change and an irreversible change.