0.07g of a hydride of carbon occupies 56.0cm3 at S.T.P. when vaporized and contains 14.29% by mass of hydrocarbon is(C = 12, H = 1)
A. CH4 B. C2H2 C. C2H4 D. C2H6 E. C3H8
Correct Answer: C
Explanation
% of H2 = 14.29 % of C = 85.71 Divided by At wts For H = (14.29)/(1) = 14.29 For C = (85.71)/(12) = 7.14 Dividing by smallest number we have the following: For H (14.29)/(7.14) = 2 For C = (7.14)/(7.14) = 1 Emperical formula of the comp = CH2 wt of hydride taht will occupy 22400 cm is 22400 x 0.7 56 = 28 = mole wt of hydride X(CH2) = 28 X(12 + 2) = 28 i.e 14x = 28x = 2 The formula of hydrocarbon is therefore C2H4
