Enantiomers are pairs of molecules that are mirror images of each other but cannot be superimposed. They have the same chemical formula and connectivity, but differ in the spatial arrangement of their atoms. In the case of 2-chloropropanoic acid, the enantiomers refer to the two possible arrangements of the substituents around the chiral carbon, which is the carbon atom bonded to four different groups.

a) Same solubility in water:
Enantiomers of 2-chloropropanoic acid have the same functional groups and overall polarity, which means they have similar solubilities in water. Both enantiomers can form hydrogen bonds with water molecules, resulting in comparable solubility.

b) Same pKa value:
The pKa value represents the acidity or basicity of a compound. Enantiomers of 2-chloropropanoic acid have the same functional groups and similar electronic environments around the acidic proton. Therefore, they will have the same pKa value.

c) Same refractive indices:
The refractive index is a measure of how much light is bent when it passes through a substance. Enantiomers of 2-chloropropanoic acid have the same molecular structure and composition, so they will have the same refractive index.

d) Same rate of reactions with ( )-2-butanol:
The correct answer is option 'D'. Enantiomers of 2-chloropropanoic acid will have different rates of reaction with ( )-2-butanol. This is because the enantiomers have different spatial arrangements of the atoms, resulting in different three-dimensional shapes. The three-dimensional shape of a molecule plays a crucial role in determining its reactivity. Since ( )-2-butanol is a chiral compound, it will interact differently with each enantiomer of 2-chloropropanoic acid, leading to different reaction rates.

In conclusion, the enantiomers of 2-chloropropanoic acid have the same solubility in water, same pKa value, and same refractive indices. However, they have different rates of reaction with ( )-2-butanol due to their different three-dimensional shapes.

Be coz that is not very reactive in nature and it contains 2 butanol. It is less reactive in nature and have 1 and only butanol