Which has the smallest orientation factor?

Question

Pick the single-step reaction that, according to collision theory, has the smallest orientation factor.

H2+H3C−CH=CH2→H3C−CH2−CH3

F+HF→F2+H

H+H→H2

All of these reactions have the same orientation factor.

Answer 1

Oh, it asked for *smallest*. The reaction with the most restrictive orientation must be the first one; the H2 has to line up at the double bond. For the second reaction, the single F atom can approach anywhere from the H side of the HF, that's more likely. And the third choice, single atoms are always aligned.

-- Cheers, -- Mr. d.