Question

When acetic acid is reacted with calcium hydroxide and the product is distilled dry, the compound formed is:
(A) Calcium acetate
(B) Acetone
(C) Acetaldehyde
(D) Acetic anhydride

Answer 1

You can start by describing why this reaction is important industrially, then you can move on to describe the molecular formula of all the reactants and products. Follow it up by showing the 2 step reaction and the condition in which they occur.

Complete step by step solution:

The reaction of acetic acid and calcium hydroxide produces calcium acetate, on dry distillation acetone and calcium carbonate. Calcium acetate is used to control high levels of phosphorus in the blood, calcium carbonate is used in the construction industry and acetone is used as a solvent for synthetic fibers and plastics. So this reaction is a very important reaction industrially.
- The molecular formula for acetic acid is $C{H_3}COOH$.
- The molecular formula for calcium hydroxide is $Ca{(OH)_2}$.
- The molecular formula of calcium acetate is $Ca{(OCOC{H_3})_2}$.
- The molecular formula of calcium carbonate is $CaC{O_3}$.
- The molecular formula of acetone is $C{H_3}COC{H_3}$.
- The reaction occurs in two steps –
$2C{H_3}COOH + Ca{(OH)_2}\xrightarrow{{}}Ca{(OCOC{H_3})_2} + 2{H_2}O$
$Ca{(OCOC{H_3})_2}\xrightarrow[{DryDistillation}]{\Delta }C{H_3}COC{H_3} + CaC{O_3}$

Note: In the second step of the reaction above, it may be noted that we use the method of dry distillation in addition to heating. Dry distillation is the process by which solid materials are heated up to convert them into their gaseous form and then condensed to form liquid or gas. This technique is helpful to separate mixtures of substances in which there is a significant difference in the boiling point of the components. In the second reaction, we use it to separate acetone from calcium carbonate that is formed on heating calcium acetate. Acetone has very low boiling point in comparison to calcium carbonate so they can be easily separated by using dry distillation.