Question

According to MOT,$C_2$ molecule has

• A. one $\sigma$ and one $\pi$-bond.
• B. only two $\pi -bonds.$
• C. only two $\sigma -bonds.$
• D. one $\sigma$ and two $\pi$ bonds.

Answer 1

Answer: (B)

$C_2(12)=\sigma 1s^2,{\sigma }^{\ast }1s^2,\sigma 2s^2,{\sigma }^{\ast }2s^2,\pi 2p_x^2\approx \pi 2p_y^2$
$C_2$ has two pairs of electrons in $\pi 2p_{x}and\pi 2p_y$ therefore, it has only two $\pi$-bonds.