Question

Identify the correct orders for the given properties. I. C-H<C-O<N-O<C-C (Bond length) {II. } H_2S<O_3<NO_2<CO_2 (Bond angle) {III. } He_2^+<B_2<C_2<N_2 (Bond order)

• A. I, II only
• B. I, III only
• C. II, III only
• D. I, II, III

Hint:

Bond order: \[ BO=\frac{N_b-N_a}{2} \] Higher bond order implies stronger bond and shorter bond length.

Answer 1

The Correct Option is D

Step 1: Check bond length order.
Bond length generally decreases with increasing bond strength. Approximate values: \[ C-H\approx1.09\AA \] \[ N-O\approx1.21\AA \] \[ C-O\approx1.43\AA \] \[ C-C\approx1.54\AA \] Hence, \[ C-H<N-O<C-O<C-C. \] Statement I is correct.

Step 2: Check bond angle order.
\[ H_2S\approx92^\circ \] \[ O_3\approx117^\circ \] \[ NO_2\approx134^\circ \] \[ CO_2=180^\circ \] Thus, \[ H_2S<O_3<NO_2<CO_2. \] Statement II is correct.

Step 3: Check bond order values.
\[ He_2^+=0.5 \] \[ B_2=1 \] \[ C_2=2 \] \[ N_2=3 \] Therefore, \[ He_2^+<B_2<C_2<N_2. \] Statement III is correct. Hence, \[ \boxed{\text{I, II and III}} \]