20.The molecular formulas andCNMR data pm)are given below. CH1o:25.2.41.9(d,48.50).135.2(d D) E) Ans:A Ans:B 22.The natural abundance ofC is A)2.1%B)10%C1.5%D)1.1%E)16% Ans:D Page 13 Page 13 20. The molecular formulas and 13C NMR data (in ppm) are given below. The splitting pattern of each signal, taken from the non-decoupled spectrum is given in parentheses. Deduce the correct structure: C7H10: 25.2 (t), 41.9 (d), 48.5 (t), 135.2 (d) A) B) C) D) E) Ans: A 21. 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 Ans: B 22. The natural abundance of 13C is A) 2.1% B) 10% C) 1.5% D) 1.1% E) 16% Ans: D