Question 2
Chemical Formulae and Equations0.07 g of a hydride of carbon occupies 56.0 cm3 at S.T.P. when vaporized and contains 14.29% by mass of hydrogen. The formula of the hydrocarbon is (C = 12, H = 1)
- A.CH4
- B.C2H2
- C.C2H4
- D.C2H6
- E.C3H8
Show the answer and explanation
Answer: C (C2H4)
Explanation
Molar mass = 0.07 × 22400/56 = 28 g. H : C = 14.29/1 : 85.71/12 = 2 : 1, so the empirical formula is CH2 (14) and the molecule is (CH2)2 = C2H4.