Paper 1 · Specimen 2018 · Chemistry
An organic compound contains 84 % carbon(C) and 16 % hydrogen (H) by mass.
[atomic mass of C is 12 and that of H is 1]
What is the empirical formula of the organic compound?
ACH
B
C
D
Explanation
Moles: C 84/12 = 7, H 16/1 = 16, a ratio of 7 : 16, which simplifies no further and is not offered. The nearest offered ratio is about 1 : 2, so the intended answer is CH2 (the setter probably meant 85.7 % C and 14.3 % H).
ZIMSEC Combined Science 4003/1, Specimen Paper 2018, Q18