August 2019 Chemistry Regent Exam
Write the general formula for the homologous series to which propene belongs.
Answer: This questions mentions homologous series, which are groups of organic compounds. We can look at the Regent Reference Table Q, that is titled "Homologous Series of Hydrocarbons" to figure out the answer to this question. Propene is an organic molecule that has an ending "ene", which means its belongs to the homologues series of alkenes. Table Q shows us the name, general formula, and examples of each homologues series. For alkenes, we see that the general formula is CnH2n. Therefore, the answer to this question is CnH2n.
We should also note that we need to remember that both alkenes and alkynes are considered unsaturated compounds, while alkanes are considered saturated compounds. Regents oftentimes ask to deduce which compound is saturate or unsaturated.