Question

A little bit of help, please? Thanks!

Answer 1

(2) An optically inactive compound

Explanation:

Lindlar's catalyst is used in order to hydrogenate alkynes into cis (or Z) alkenes.

So, first, we observe that there is one (and only one) chiral centre in the molecule, which is the carbon with 4 single bonds.

The products formed from the reaction will not have this chiral centre anymore. This is because the `MeC_2` substituent will be hydrogenated into `Me(CH)_2`, which is the same as the right (both are Z-enantiomers).

Therefore, the product will be optically inactive due to not having a chiral centre.