NEETChemistryChemical Bonding and Molecular Structure
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The carbon molecule ( C ₂ ) has a bond order of 2 and its double bond consists entirely of -bonds. Reason (R): In the molecular orbital configuration of C ₂ , the four valence electrons of the 2p subshell occupy the _ 2p_x and _ 2p_y orbitals, leaving the _ 2p_z orbital empty. In the light of the a
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is correct but (R) is not correct
- D(A) is not correct but (R) is correct
Correct answer
A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
Step-by-step solution
Assertion (A) is correct. The C ₂ molecule has 12 electrons. Its molecular orbital configuration is _ 1s ^2 _ 1s ^ *2 _ 2s ^2 _ 2s ^ *2 _ 2p_x ^2 = _ 2p_y ^2 . The bond order is 8 - 4 2 = 2 . Since the last four electrons enter the molecular orbitals, the double bond in C ₂ consists of two -bonds. Reason (R) is also correct and provides the exact explanation for (A). The fact that the four 2p electrons are accommodated in the degenerate _ 2p_x and _ 2p_y orbitals while the _ 2p_z orbital remains empty is the reason