The NMR peak intensities for a first-order quartet are:
A) 1:2:2:1
B) 1:3:3:1
C) 1:4:4:1
D) 1:1:1:1
E) None of the above.

Question

Quizplus · Accepted Answer

The peak intensities for a first-order quartet can be calculated using the binomial coefficients (n+1) choose k, where n is the number of nuclei equivalent to the quartet and k is the position of the peak intensity. For a quartet, n=3 and the peak intensities are 1:3:3:1, which corresponds to choice B.

The NMR Peak Intensities for a First-Order Quartet Are