Question

which of the following is a combustion reaction?
c10h16 (l) + 8 cl2 (l) → 10 c (s) + 16 hcl (aq)
6 co2 (g) + 6 h2o (g) → c6h12o6 (s) + 6 o2 (g)
naoh (aq) + hcl (aq) → nacl (aq) + h2o (l)
c7h16 (l) + 11 o2 (g) → 7 co2 (g) + 8 h2o (g)

Explanation:

Step1: Recall combustion reaction definition

Combustion reaction: substance reacts with \(O_2\), usually produces \(CO_2\) and \(H_2O\).

Step2: Analyze each option

• Option A: Reactant has \(Cl_2\) (not \(O_2\)), not combustion.
• Option B: Reverse of photosynthesis (not reaction with \(O_2\)), not combustion.
• Option C: Acid - base neutralization (\(NaOH + HCl\)), not combustion.
• Option D: \(C_7H_{16}\) reacts with \(O_2\) to form \(CO_2\) and \(H_2O\), fits combustion.

Answer:

D. \(C_7H_{16(l)} + 11O_{2(g)} \to 7CO_{2(g)} + 8H_2O_{(g)}\)