Question

Give the molecular formula of a hydrocarbon containing five carbon atoms that is (a) an alkane, (b) a cycloalkane, (c) an alkene, (d) an alkyne.

Short answer

The molecular formulas for hydrocarbons containing five carbon atoms are as follows: (a) Alkane: \(C_5H_{12}\) (b) Cycloalkane: \(C_5H_{10}\) (c) Alkene: \(C_5H_{10}\) (d) Alkyne: \(C_5H_8\)

Step-by-step solution

(a) Alkane formula

For an alkane with five carbon atoms, we apply the general formula of an alkane, CnH(2n+2), where 'n' equals 5. Plugging the value of n into the formula, we get: C5H[2(5)+2] = C5H12 Hence, the molecular formula of an alkane containing five carbon atoms is C5H12.

(b) Cycloalkane formula

For a cycloalkane with five carbon atoms, we apply the general formula of a cycloalkane, CnH2n, where 'n' equals 5. Plugging the value of n into the formula, we get: C5H(2 * 5) = C5H10 Hence, the molecular formula of a cycloalkane containing five carbon atoms is C5H10.

(c) Alkene formula

For an alkene with five carbon atoms, we apply the general formula of an alkene, CnH2n, where 'n' equals 5. Plugging the value of n into the formula, we get: C5H(2 * 5) = C5H10 Hence, the molecular formula of an alkene containing five carbon atoms is C5H10.

(d) Alkyne formula

For an alkyne with five carbon atoms, we apply the general formula of an alkyne, CnH(2n-2), where 'n' equals 5. Plugging the value of n into the formula, we get: C5H[2(5) - 2] = C5H8 Hence, the molecular formula of an alkyne containing five carbon atoms is C5H8.