See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

Concept: When a racemic mixture (d and l) of one compound reacts with an optically pure (single enantiomer) reagent, the products formed are diastereomers. Step 1: Identify the reactants. The amine is a racemic mixture (d-amine + l-amine), and the acid is a single enantiomer (l-acid only). Step 2: Consider the reactions separately. - d-amine + l-acid → one salt/product (e.g., d,l-combination) - l-amine + l-acid → another salt/product (e.g., l,l-combination) Step 3: Analyze the products. The two products formed have the same connectivity (same sequence of bonds) but differ in the spatial arrangement of atoms at their stereocenters. Specifically, one product has (d,l) configuration and the other has (l,l) configuration. These are non-superimposable, non-mirror-image stereoisomers — which is the definition of diastereomers. Step 4: Rule out other options. - Meso: Would require internal symmetry canceling chirality; not applicable here since we have two distinct chiral centers from different sources. - Racemic: A racemic mixture consists of equal amounts of two enantiomers (mirror images). The two products here are NOT mirror images of each other, so it is not racemic. - Pure Enantiomer: A pure enantiomer would result if only one chiral product formed; here two different (diastereomeric) products form. Therefore, the correct answer is A.