Q.What happens when a mixture of calcium formate and calcium acetate is dry distilled?

Heating (dry-distilling) calcium acetate decomposes it into acetone and calcium carbonate — this is a classical laboratory method for preparing ketones from the calcium salts of carboxylic acids.

Calcium acetate, (CH3COO)2Ca, when strongly heated in the absence of air (dry distillation), decomposes as follows:

(CH3COO)2Ca --heat--> CH3-CO-CH3 (acetone) + CaCO3

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Dry-distilling a 1:1 mixture of calcium formate and calcium acetate is a classical method for preparing acetaldehyde.

Dry distillation of the calcium salt of a carboxylic acid alone typically gives a symmetrical ketone (e.g., calcium acetate alone gives acetone). But when calcium formate (the calcium salt of formic acid, HCOOH) is dry-distilled together with calcium acetate (calcium salt of acetic acid, CH3COOH), a 'mixed' or 'cross' pyrolysis occurs. Because formate provides the H-C(=O)- fragment, the product is an aldehyde rather than a ketone:

(HCOO)2Ca + (CH3COO)2Ca --Delta (dry distillation)--> 2 CH3CHO (acetaldehyde) + 2 CaCO3

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Dry distillation of calcium acetate produces acetone (propan-2-one).

Calcium acetate is the calcium salt of acetic acid, (CH3COO)2Ca. When it is heated strongly in the absence of water (dry distillation), the two acetate groups combine, losing a carbonate, and a ketone is formed:

(CH3COO)2Ca --(heat)--> CH3-CO-CH3 + CaCO3

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