What is the general formula for alkynes?

What is the general formula for alkynes?

• A. CnH2n
• B. CnH2n+2
• C. CnH2n-2
• D. CnH2n-1

Answer: (C)

The general formula for alkynes is CnH2n-2. Alkynes are hydrocarbons that contain at least one carbon-carbon triple bond. In the formula, 'n' represents the number of carbon atoms in the molecule. Since each triple bond between carbon atoms leads to a reduction of two hydrogen atoms compared to the alkane (which has the formula CnH2n+2), the formula for alkynes accounts for this decrease in hydrogen by subtracting two from the hydrogen count. For example, if there are two carbon atoms (n=2), the hydrogen count is calculated as follows: H = 2(2) - 2 = 2. This means that the simplest alkyne, ethyne (commonly known as acetylene), has two carbon atoms and two hydrogen atoms (C2H2). Understanding this formula is crucial for correctly identifying, naming, and drawing structures of alkyne compounds in organic chemistry.

The general formula for alkynes is CnH2n-2. Alkynes are hydrocarbons that contain at least one carbon-carbon triple bond. In the formula, 'n' represents the number of carbon atoms in the molecule. Since each triple bond between carbon atoms leads to a reduction of two hydrogen atoms compared to the alkane (which has the formula CnH2n+2), the formula for alkynes accounts for this decrease in hydrogen by subtracting two from the hydrogen count.

For example, if there are two carbon atoms (n=2), the hydrogen count is calculated as follows: H = 2(2) - 2 = 2. This means that the simplest alkyne, ethyne (commonly known as acetylene), has two carbon atoms and two hydrogen atoms (C2H2).

Understanding this formula is crucial for correctly identifying, naming, and drawing structures of alkyne compounds in organic chemistry.