Question Detail
Question
A compound, C15H24, is reacted with excess hydrogen using a metal catalyst. One equivalent of the compound consumed three equivalents of hydrogen. How many rings did the original compound have?
Correct Answer
Option A is the correct answer.
Detailed Explanation
The formula C15H24 has a degree of unsaturation (DBE) = (2C+2-H)/2 = (30+2-24)/2 = 8/2 = 4. Three equivalents of H2 consumed means 3 degrees of unsaturation are from double/triple bonds (each H2 adds to a π bond). The remaining 1 degree of unsaturation must be from a ring. So the compound has 1 ring.
Hint
How is degree of unsaturation calculated, and how does H2 consumption relate to it?