Catalysts: Heterogeneous vs. Homogeneous

Steps:

• Define heterogeneous catalyst as one in a different phase from reactants (e.g., solid with gases); homogeneous as same phase (e.g., all gases).
• Analyze reaction 1: Fe(s) is solid catalyst, N2(g) and H2(g) are gases, so different phases—heterogeneous.
• Analyze reaction 2: Vaporized tetrachloroethane is gaseous catalyst under UV light, implying gaseous reactants (photochemical process), so same phase—homogeneous.
• Match to options: Reaction 1 heterogeneous, reaction 2 homogeneous, selecting C.

Why C is correct:

• Heterogeneous catalysts differ in phase from reactants (Fe solid vs. gases); homogeneous match phases (vaporized catalyst with likely gaseous reactants).

Why the others are wrong:

• A: Reaction 2 uses homogeneous catalyst, not heterogeneous.
• B: Reaction 1 uses heterogeneous catalyst, not homogeneous.
• D: Reverses the catalyst types for each reaction.

Final answer: C