If a certain hydrocarbon molecule has 10 carbons atoms, one ring and two triple bonds, how many hydrogens does it have?
A) 10
B) 12
C) 14
D) 16
E) 18

Question

Quizplus · Accepted Answer

The hydrocarbon in question follows the general formula for calculating hydrogen atoms in a hydrocarbon, which is CnH2n+2 for alkanes. However, since this molecule has a ring and two triple bonds, we need to adjust this formula. Each ring or triple bond acts like a degree of unsaturation, reducing the number of hydrogen atoms by 2 for each. Therefore, starting with an alkane base of C10H22, we subtract 2 hydrogens for the ring and 4 hydrogens for the two triple bonds (2 for each), resulting in C10H16. However, since triple bonds actually reduce the hydrogen count by 4 per bond (not 2, as initially calculated), we need to correct the calculation: Starting again from C10H22, subtracting 2 for the ring and 8 for the two triple bonds (4 for each) gives us C10H12.

If a Certain Hydrocarbon Molecule Has 10 Carbons Atoms, One