When calcium propanoate is distilled, the product obtained is (a) 2 -pentanone (b) 3 -pentanone (c) propanal (d) propanone

Calcium propanoate or calcium propionate has the chemical formula Ca(C2H5COO)2. It is made up of a calcium ion (Ca2+) and two propanoate ions (C2H5COO-). The propanoate ion has the structure: CH3CH2COO- In order to determine the product obtained when distilling calcium propanoate, we need to analyze the chemical changes that occur during the distillation process.

Distillation is a process that typically involves heating a liquid to form vapor, then cooling the vapor to collect the purified product. However, in the case of calcium propanoate, it undergoes a process called decarboxylation when heated. Decarboxylation is the removal of a carboxyl group (COOH) from the molecule, resulting in the release of carbon dioxide (CO2) and a new organic molecule. Note that in the case of calcium propanoate, we are working with carboxylate ions (COO-), but the principle of decarboxylation remains the same.

When calcium propanoate undergoes decarboxylation, the carboxylate ion (COO-) is lost, and two propanoate ions (C2H5COO-) combine to form a new organic molecule. Let's analyze each of the given options: (a) 2-pentanone has the structure CH3CH2CH2COCH3. This molecule can be formed by joining two propanoate ions at the carbonyl group after losing the carboxylate ions. It's a possible product of the decarboxylation process. (b) 3-pentanone has the structure CH3CH2COCH2CH3. This molecule cannot be formed from the distillation of calcium propanoate as it would require a different distribution of carbons and a loss of a different group. (c) Propanal has the structure CH3CH2CHO. This molecule cannot be formed from the distillation of calcium propanoate as it would require the addition of an aldehyde group instead of removing a carboxylate group. (d) Propanone has the structure CH3COCH3. This molecule also cannot be formed from the distillation of calcium propanoate as it would require a different distribution of carbons.

Based on the analysis done in Step 3, the product obtained when calcium propanoate is distilled is 2-pentanone. Therefore, the correct answer is option (a) 2-pentanone.