Question

Octet rule is obeyed in

• A. $SCl_2$
• B. $PF_5$
• C. $SF_6$
• D. $BCl_3$
• E. $H_2SO_4$

Hint:

Elements in period 3 and beyond can have expanded octets due to available d-orbitals.

Answer 1

The Correct Option is A

Step 1: The octet rule states that atoms tend to form bonds in such a way that they achieve a stable electron configuration with 8 valence electrons. Step 2: In $SCl_2$ (Sulfur dichloride), sulfur forms two single bonds with chlorine, fulfilling its octet requirement (6 valence electrons + 2 shared electrons = 8). 
Step 3: The other molecules: - $PF_5$ and $SF_6$ have expanded octets. 
- $BCl_3$ does not complete the octet (Boron has only 6 valence electrons). 
- $H_2SO_4$ involves delocalized bonding and resonance. 
Step 4: Since only $SCl_2$ strictly follows the octet rule, the correct answer is (A).