Question

Acetylene (C2H2) has a tendency to lose two protons (H1) and form the carbide ion (C2 22), which is present in a number of ionic compounds, such as CaC2 and MgC2. Describe the bonding scheme in the C2 22 ion in terms of molecular orbital theory. Compare the bond order in C2 22 with that in C2.

Answer 1

Answer:

The C22- ion is stable

Explanation:

The C22- ion is a stable ion having a bond order of three. It has a favourable stabilization energy of 6∆ compared to 4∆ in C2. In the carbide ion carbon firms three bonds rather than two in dicarbon, hence the formation of the carbide ion is preferred. The molecular orbital configuration of the carbide ion is shown in the image attached.