What is the empirical formula for C4H8?
The Correct Answer and Explanation is:
Correct Answer:
The empirical formula for C₄H₈ is CH₂.
Explanation:
To find the empirical formula of a compound, we must reduce the molecular formula to its simplest whole number ratio. The molecular formula of the compound is C₄H₈, which means it contains 4 carbon atoms and 8 hydrogen atoms.
The next step is to identify the greatest common factor (GCF) of the subscripts (4 and 8). The GCF of 4 and 8 is 4. We divide each subscript in the formula by 4:
- Carbon: 4 ÷ 4 = 1
- Hydrogen: 8 ÷ 4 = 2
This gives us the ratio 1 carbon atom to 2 hydrogen atoms. Therefore, the empirical formula is CH₂.
The empirical formula represents the simplest whole-number ratio of elements in a compound, not necessarily the actual number of atoms in a molecule. For instance, C₄H₈ is the molecular formula of several different compounds, such as butene and cyclobutane, but they all share the same empirical formula, CH₂.
This empirical formula gives useful information about the basic composition of a compound. While the molecular formula gives the actual number of atoms, the empirical formula helps chemists understand the basic proportionality of elements present. For example, knowing that a compound has an empirical formula of CH₂ tells you that for every one carbon atom, there are two hydrogen atoms, no matter how many total atoms are in a molecule of the substance.
In summary, C₄H₈ simplifies to CH₂ when we reduce the carbon to hydrogen ratio to its lowest whole number terms. This makes CH₂ the correct empirical formula.
