Question

Ethylene dibromide on heating with metallic sodium in ether solution yields
A. Ethene
B. Ethyne
C. 2-butene
D. 1-butene

Answer 1

Hint: When ethylene dibromide is heated with metallic sodium in presence of ether solution, the product formed is an unsaturated hydrocarbon. The reaction involved is a type of elimination reaction.

Complete Step by Step Solution:
By the name ethylene dibromide it is clear that the hydrocarbon is ethane so the number of carbon atoms is two and di- means two, so the number of bromine atoms present is two.
An elimination reaction is a type of reaction where one or two atoms from the adjacent carbon of the reactant are removed to form a new product.

In the given reaction ether is used as a solvent.
The reaction of ethylene dibromide with metallic sodium in ether is shown below.
\[2C{H_3}CHB{r_2} + 4Na \xrightarrow[\Delta ]{ether} C{H_3} - CH = CH - C{H_3} + 4NaBr\]
In the given reaction ethylene dibromide on heating with metallic sodium in ether solution gives ethene as the main product by elimination of sodium bromide.

Ethene is an unsaturated hydrocarbon containing two carbon atoms bonded together by a double bond. Ethene is also known as ethylene.
Therefore, the correct option is A.

Note: Make sure not to get confused between ethane, ethene and ethyne. Ethane is an alkane with a carbon-carbon single bond. It is a saturated hydrocarbon. Ethene is an alkene with a carbon-carbon double bond. It is an unsaturated hydrocarbon and ethyne is an alkyne with a carbon-carbon double bond. It is also an unsaturated hydrocarbon.