Answer:
a) The empirical formula of the hydrocarbon is CH4.
b) The molecular formula of the hydrocarbon is (CH4) * 1.875 = C1.75H7
Step-by-step explanation:
(a) To find the empirical formula of the hydrocarbon, we can follow these steps:
Convert the percentages of each element to grams: 80% C = 0.8 * 12 g/mol = 9.6 g C, and 20% H = 0.2 * 1 g/mol = 0.2 g H.
Calculate the number of moles of each element: 9.6 g C / 12 g/mol = 0.8 mol C, and 0.2 g H / 1 g/mol = 0.2 mol H.
Divide each number of moles by the smallest number of moles to find the ratio of the elements: 0.8 mol C / 0.2 mol H = 4, and 0.2 mol H / 0.2 mol H = 1.
(b) To find the molecular formula of the hydrocarbon, we need to know the relative molecular mass (RMM) of the compound, which is given as 30. The empirical formula of the compound is CH4, which has a RMM of 12 + 4 = 16. To find the molecular formula, we need to multiply the empirical formula by a factor that will give us the correct RMM. In this case, we can multiply the empirical formula by a factor of 30 / 16 = 1.875. Multiplying the empirical formula by this factor gives us a molecular formula of (CH4) * 1.875 = C1.75H7.