The chemical formula of propene is:
C3H6
Understanding the Chemical Formula of Propene
To determine the chemical formula of propene, we first need to identify the type of hydrocarbon it is and the number of carbon atoms it contains.
Identifying Propene as an Alkene
The name 'propene' ends with the suffix '-ene'. This suffix indicates that the molecule is an alkene. Alkenes are a class of hydrocarbons that contain at least one carbon-carbon double bond ($\text{C}=\text{C}$).
General Formula for Alkenes
Alkenes that have only one double bond and are not cyclic follow a general chemical formula. This formula relates the number of carbon atoms ($\text{n}$) to the number of hydrogen atoms.
The general formula for straight-chain or branched alkenes with one double bond is $\text{C}_{\text{n}}\text{H}_{2\text{n}}$, where $\text{n}$ represents the number of carbon atoms.
Determining the Number of Carbon Atoms in Propene
The prefix 'prop-' in organic chemistry names signifies a chain of three carbon atoms. So, for propene, the number of carbon atoms ($\text{n}$) is 3.
Calculating the Chemical Formula of Propene
Now we can substitute the value of $\text{n} = 3$ into the general formula for alkenes, $\text{C}_{\text{n}}\text{H}_{2\text{n}}$:
Number of carbon atoms ($\text{n}$) = 3
Number of hydrogen atoms = $2 \times \text{n} = 2 \times 3 = 6$
Therefore, the chemical formula for propene is $\text{C}_3\text{H}_6$.
Comparing with Options
Let's compare our calculated formula with the given options:
- Option 1: $\text{C}_2\text{H}_4$ (This is Ethene, $\text{n}=2$)
- Option 2: $\text{C}_3\text{H}_4$ (This formula fits an alkyne with 3 carbons, Propyne)
- Option 3: $\text{C}_3\text{H}_6$ (This matches our calculation for Propene)
- Option 4: $\text{C}_2\text{H}_2$ (This is Ethyne, $\text{n}=2$, an alkyne)
The calculated formula $\text{C}_3\text{H}_6$ matches Option 3.
Conclusion on Propene's Formula
Based on the rules of organic nomenclature and the general formula for alkenes, the chemical formula for propene (with three carbon atoms and one double bond) is $\text{C}_3\text{H}_6$.
Revision Table: Hydrocarbon Series
| Series | Suffix | General Formula (non-cyclic) | Example ($\text{n}=2$) | Example ($\text{n}=3$) |
|---|---|---|---|---|
| Alkanes | -ane | $\text{C}_{\text{n}}\text{H}_{2\text{n}+2}$ | Ethane ($\text{C}_2\text{H}_6$) | Propane ($\text{C}_3\text{H}_8$) |
| Alkenes | -ene | $\text{C}_{\text{n}}\text{H}_{2\text{n}}$ | Ethene ($\text{C}_2\text{H}_4$) | Propene ($\text{C}_3\text{H}_6$) |
| Alkynes | -yne | $\text{C}_{\text{n}}\text{H}_{2\text{n}-2}$ | Ethyne ($\text{C}_2\text{H}_2$) | Propyne ($\text{C}_3\text{H}_4$) |
Additional Information on Alkenes and Propene
- Alkenes are unsaturated hydrocarbons because they contain a double bond, meaning they could theoretically hold more hydrogen atoms if the double bond were broken.
- The simplest alkene is ethene ($\text{C}_2\text{H}_4$), also commonly known as ethylene. The 'meth-' prefix (for one carbon) is not used for alkenes or alkynes because a double or triple bond requires at least two carbon atoms.
- Propene ($\text{C}_3\text{H}_6$) is an important industrial chemical used in the production of plastics like polypropylene.
- The position of the double bond matters for alkenes with four or more carbon atoms, leading to isomers (molecules with the same chemical formula but different structures), but for propene ($\text{C}_3\text{H}_6$), there is only one possible structure.
Important Questions from Hydrocarbons
The number of structural isomers of pentane is
- Refining of petroleum is carried out using which one of the following techniques?
Directions: The following 05 (Five) items consist of two statements, Statement I and Statement II. Examine these two statements carefully and select the answers to these items using the code given below:
Statement I: Petroleum is a mixture of many different hydrocarbons of different densities.
Statement II: The grade of petroleum depends mainly on the relative proportion of the different hydrocarbons.
How many carbon and hydrogen atoms are there in Propane, respectively?
In 1931, who recognised that an aromatic compound must have an odd number of pairs of electrons, which can mathematically be written as 4n + 2 (n = 0, 1, 2, 3 etc.)?
