Question

Ethyne differs from ethene in what way? A. The carbons share three pairs of electrons in ethyne and only two pairs in ethene. B. The carbons in ethyne each form three single bonds whereas those in ethene each form four single bonds. C. The carbons in ethyne are not fixed in place as they are in ethene. D. Ethyne contains only carbon and hydrogen atoms.

Answer 1

A. The carbons share three pairs of electrons in ethyne and only two pairs in ethene

Step-by-step explanation:

Both ethene and ethyne are hydrocarbons i.e. they contain C and H.

Ethene belongs to the alkene series with a formula C2H4. Here the carbon atoms are linked together via a double bond and carbon and hydrogens are linked via a single bond.

Ethyne belongs to the alkyne series with a formula C2H2. The C atoms are linked by a triple bond and carbon and hydrogens are linked via a single bond.

Since each bond constitutes a pair of electrons, accordingly the carbons share three pairs of electrons in ethyne and only two pairs in ethene.

Answer 2

The correct answer is A. The carbons in ethyne share three pairs of electrons which makes it an alkyne while in ethene only two pair of electrons are being shared by the two carbon atoms. In other words, ethyne contains a triple bond while ethene contains a double bond.