Problem 14 - Chemistry: The Central Science

Question

Give the molecular formula of a cyclic alkane, a cyclic alkene, a linear alkyne, and an aromatic hydrocarbon that in each case contains six carbon atoms. Which are saturated and which are unsaturated hydrocarbons?

Step-by-Step Solution

Answer

The molecular formulas for each hydrocarbon with six carbon atoms are: - Cyclic Alkane: \(C_6H_{12}\) (saturated) - Cyclic Alkene: \(C_6H_{10}\) (unsaturated) - Linear Alkyne: \(C_6H_{10}\) (unsaturated) - Aromatic Hydrocarbon (Benzene): \(C_6H_{6}\) (unsaturated) Saturated hydrocarbon: Cyclic Alkane Unsaturated hydrocarbons: Cyclic Alkene, Linear Alkyne, Aromatic Hydrocarbon (Benzene)

Step 1: Cyclic Alkane Molecular Formula

A cyclic alkane, also known as a cycloalkane, has carbon atoms connected in a ring structure. It contains only single bonds. The general formula for a cycloalkane is CnH2n, where n is the number of carbon atoms. In this case, we have six carbon atoms, so n = 6: Cyclic Alkane Molecular Formula: C_6H_{2(6)} = C_6H_{12}

Step 2: Cyclic Alkene Molecular Formula

A cyclic alkene, also known as a cycloalkene, has carbon atoms connected in a ring structure with one double bond between two carbons. The general formula for a cyclic alkene is CnH2n-2, where n is the number of carbon atoms. In this case, we have six carbon atoms, so n = 6: Cyclic Alkene Molecular Formula: C_6H_{2(6)-2} = C_6H_{10}

Step 3: Linear Alkyne Molecular Formula

A linear alkyne is a hydrocarbon with carbon atoms connected linearly, containing at least one triple bond between two carbons. The general formula for an alkyne is CnH2n-2, where n is the number of carbon atoms. In this case, we have six carbon atoms and one triple bond, so n = 6: Linear Alkyne Molecular Formula: C_6H_{2(6)-2} = C_6H_{10}

Step 4: Aromatic Hydrocarbon Molecular Formula

An aromatic hydrocarbon, also known as an arene, usually contains a ring of carbon atoms with alternating single and double bonds. A common example of an aromatic hydrocarbon with six carbon atoms is benzene. Benzene Molecular Formula: C_6H_6

Step 5: Identify Saturated and Unsaturated Hydrocarbons

Saturated hydrocarbons contain only single bonds between carbon atoms, while unsaturated hydrocarbons contain at least one double or triple bond. From our list, the cyclic alkane (C_6H_{12}) is a saturated hydrocarbon because it has only single bonds. Cyclic alkene (C_6H_{10}), linear alkyne (C_6H_{10}), and aromatic hydrocarbon (C_6H_6) are unsaturated hydrocarbons because they contain one or more double and/or triple bonds between carbon atoms.