Question

Which hybrid orbitals are used to form the sigma bonds between the carbons in acetylene? (BLB Ch. 9) are used to form the pi bonds between the carbons in acetylene?

Answer 1

Answer:

sp hybrid orbitals

Explanation:

Acetylene molecule is linear in shape which means that all the four atoms lie in the straight line.

Carbon-carbon triple bond is 1.20Å long only. In acetylene, both the carbons are sp-hybridized which means that s orbital overlaps with one p orbital only. 2s orbital in sp-hybridized carbon combines with $2p_x$ orbital and two sp hybrid orbitals are formed which are oriented at the angle of 180° . One is bonded to hydrogen and another to the carbon. $2p_z$ and $2p_y$ orbitals remain non-hybridized and thus are oriented perpendicularly along z and y axes respectively.