Question

Which of the following equations is \emph{not balanced?}

• A. 2H\textsubscript{2} + O\textsubscript{2} $\rightarrow$ 2H\textsubscript{2}O
• B. 2KClO\textsubscript{3} $\rightarrow$ 2KCl + 3O\textsubscript{2}
• C. H\textsubscript{2} + Cl\textsubscript{2} $\rightarrow$ 2HCl
• D. Pb(NO\textsubscript{3})\textsubscript{2} $\rightarrow$ PbO + NO\textsubscript{2} + O\textsubscript{2}

Hint:

Always tally each element’s atoms on LHS and RHS to check balance.

Answer 1

The Correct Option is D

Step 1: Count atoms on each side.
LHS: Pb=1, N=2, O=6.
RHS: Pb=1, N=1 (in NO\textsubscript{2}), O=5 (1 in PbO, 2 in NO\textsubscript{2}, 2 in O\textsubscript{2}).
Step 2: Observation.
N and O counts differ, so the equation is not balanced. Others are balanced.
Step 3: Conclusion.
Thus option (4) is not balanced.