Answer to Question #116363 in General Chemistry for maria

Question

One of the amino acids contains 52.16% C, 7.88% H, 12.17% N and the rest is O. Its molar mass is 115.13 g/mol. What is the molecular formula of this amino acid? Steps of calculation must be typed to earn the full points.

Answer 1

1) ω(O)=100% - (ω(C)+ω(H)+ω(N))=100-(52+7.88+12.17)=27.95%;

2) C_xH_yN_zO_d

x:y:z:d=(52.16/12) : (7.88/1) : (12.17/14) : (27.95/16)=4.3467 : 7.88 : 0.869 : 1.747 = 5:9:1:2;

Simplest formula - C₅H₉NO₂;

3) Mr(C5H9NO2)=12*5+9+14+16*2=115 g/mol;

So C5H9NO2 is also the molecular formula;

Answer: C5H9NO2