Alkenes are a series of unsaturated hydrocarbons containing a double bond. Which formula does not represent an alkene? A. C2H4 B. C3H6 C. C4H10 D. C6H12

Alkenes are unsaturated hydrocarbons containing at least one carbon-carbon double bond. The general formula for an alkene with one double bond is $\text{C}_n\text{H}_{2n}$, where $n$ is the number of carbon atoms.

• A. $\text{C}_2\text{H}_4$ Here, $n=2$. According to the general formula, the number of hydrogen atoms should be $2n = 2 \times 2 = 4$. This matches the given formula. So, $\text{C}_2\text{H}_4$ is an alkene (ethene).

• B. $\text{C}_3\text{H}_6$ Here, $n=3$. According to the general formula, the number of hydrogen atoms should be $2n = 2 \times 3 = 6$. This matches the given formula. So, $\text{C}_3\text{H}_6$ is an alkene (propene).

• C. $\text{C}_4\text{H}_{10}$ Here, $n=4$. According to the general formula, the number of hydrogen atoms should be $2n = 2 \times 4 = 8$. The given formula has 10 hydrogen atoms, which does not match 8. This formula, $\text{C}_4\text{H}_{10}$, fits the general formula for an alkane ($\text{C}_n\text{H}_{2n+2}$), which is butane. Therefore, $\text{C}_4\text{H}_{10}$ is not an alkene.

• D. $\text{C}_6\text{H}_{12}$ Here, $n=6$. According to the general formula, the number of hydrogen atoms should be $2n = 2 \times 6 = 12$. This matches the given formula. So, $\text{C}_6\text{H}_{12}$ is an alkene (hexene).

Based on the analysis, $\text{C}_4\text{H}_{10}$ does not fit the general formula for an alkene.

The final answer is $\boxed{\text{C}}$.