Question

Methane is prepared in the laboratory by heating a mixture of sodium acetate and______.
A. Water
B. Soda lime
C. Lime stone
D. Sodium carbonate

Answer 1

Hint: Methane is the simplest hydrocarbon, consisting of one carbon atom and four hydrogen atoms. The chemical formula of methane is \[\] \[C{H_4}\]. Methane is a powerful greenhouse gas. It is colorless, odorless gas that occurs abundantly in nature and as a product of certain human activities.
The chemical formula of sodium acetate \[\left( {C{H_3}COONa} \right)\;\]

Step by step answer: In the laboratory methane is prepared by heating a mixture of sodium acetate with soda lime. Soda lime is a mixture of \[NaOH\] &\[Ca{\left( {OH} \right)_{_2}}\]. The reactants are heated in a test tube.
\[C{H_3}COONa + NaOH \to C{H_{4}} + N{a_2}C{O_3}\]
This reaction is called decarboxylation and is one of the general methods to prepare alkanes.
Hence, from the above reaction it is clear that soda lime is heated with sodium acetate to form methane.

Option (c) is the correct choice.

Additional Information: Decarboxylation is a chemical reaction that removes a carboxyl group and releases carbon dioxide (CO2). Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The term "decarboxylation" usually means replacement of a carboxyl group (-COOH) with a hydrogen atom. These reactions are one of the oldest known organic reactions.
For example- Heat sodium ethanoate with soda lime.

Note: Students may confuse between the formula of washing soda and soda lime. These are two different compounds. Soda lime is a mixture of \[NaOH\] & \[Ca{\left( {OH} \right)_{_2}}\] while chemical formula of washing soda is \[\] \[N{a_2}C{O_3}\].Both Soda lime and washing soda have different uses.