Assertion :- Compound of which mirror image is non superimposable, is called optically active.Reason :- Condition for a compound to be an optically active is that there should be chiral carbon

The assertion and the reason are both correct and the reason is the correct explanation for the assertion.

Step 1: Understanding the terms

• Optically active compounds are those that can rotate the plane of polarized light.
• A chiral carbon atom is a carbon atom that is attached to four different types of atoms or groups of atoms.

Step 2: Connecting the terms

• The presence of a chiral carbon atom in a molecule is what makes it optically active. This is because the four different groups can be arranged in two different ways around the carbon atom, creating two different molecules. These two molecules are mirror images of each other and are not superimposable, just like your left and right hands.

Step 3: Conclusion

• Therefore, the assertion that a compound is optically active if its mirror image is non-superimposable is correct. The reason given, that the compound must contain a chiral carbon atom, is also correct and is the correct explanation for the assertion.