What is the general formula of alkenes?
$C_n H_2n$
To determine the general formula for alkenes, we need to understand the structure of these hydrocarbons. Alkenes are hydrocarbons that contain at least one carbon-carbon double bond. Because of this double bond, the hydrogen content is less than that of alkanes. The general formula for alkenes is expressed as C_nH_{2n}.
Here's how we can derive this:
- Consider the simplest alkene, ethylene (also known as ethene), which has the formula C_2H_4. It fits the general formula since n = 2, leading to C_2H_{2 \times 2} = C_2H_4.
- Now consider increasing the number of carbon atoms. For propylene (propene), n = 3, which leads to C_3H_{2 \times 3} = C_3H_6.
- The pattern holds for any alkene since the double bond reduces the number of hydrogen atoms compared to alkanes, which have the formula C_nH_{2n+2}.
Therefore, the correct answer is C_nH_{2n}. This formula accounts for the double bond that reduces the number of hydrogen atoms in alkenes by 2 compared to their saturated counterparts (alkanes).
Let's rule out the other options:
- C_nH_n: This formula would not satisfy hydrocarbons with a double bond.
- C_nH_{2n+2}: This is the general formula for alkanes, not alkenes.
- C_nH_{2n-2}: This formula fits alkynes, which contain a triple bond, not alkenes.
This logical examination ensures that C_nH_{2n} is the definitive formula for alkenes.
Similar Questions
What is the main reason sulfur dioxide irritates the upper respiratory mucous membrane?
In a real-life scenario, a chemist discovers a compound with the formula $CH_3 CH_2 CH(CH_3)CH_2 CH_2 OH$. What is the correct IUPAC name for this compound?
A student accidentally spills some hydrochloric acid on a table. Which substance should be used to neutralise the acid safely?
According to Thomson’s model, how are electrons arranged in an atom?
If 10 grams of salt are dissolved in 100 mL of water, which component is the solute?
Consider the following statements regarding chemical reactions and choose the correct option.
Statement I: Every reaction in which two or more reactants combine to form a single product is classified as a combination reaction regardless of heat change.
Statement II: The reaction $CaO(s) + H_2O(l) → Ca(OH)_2 (aq)$ + heat is both a combination 2 2 reaction and an exothermic reaction.
The atmospheric component that remains largely unreactive is _____________.
Which condition is required for a displacement reaction between a metal and salt solution?
The atmospheric component that remains largely unreactive is _____________.
If 10 grams of salt are dissolved in 100 mL of water, which component is the solute?
Important Questions from Chemistry
What is deposited on iron in the process of Galvanization?
Which element is used for making solar cells?
Which gas is flushed in a bag of chips to prevent the chips from getting oxidized?
Terylene is a type of:
Who was the first Indian lady scientist who worked with organic chemistry and medicinal plant?
