Determine the empirical formula for the compound with the molecular formula B2Cl4. empirical formula: Determine the empirical formula for the compound with the molecular formula H2S2O8. empirical formula:
The Correct Answer and Explanation is:
To determine the empirical formula from the molecular formula, we need to find the simplest whole-number ratio of elements in the compound. The molecular formula gives us the actual number of atoms of each element in one molecule, while the empirical formula represents the smallest whole-number ratio of these atoms.
Example 1: B2Cl4
The molecular formula for this compound is B2Cl4.
- Identify the elements: We have boron (B) and chlorine (Cl).
- Find the ratio of atoms:
- There are 2 boron atoms and 4 chlorine atoms.
- Simplify the ratio:
- The ratio of boron to chlorine is 2:4.
- To simplify, divide both numbers by their greatest common divisor (GCD), which is 2.
- The simplified ratio is 1:2.
- Empirical formula: The empirical formula is BCl2.
Thus, the empirical formula of B2Cl4 is BCl2.
Example 2: H2S2O8
The molecular formula for this compound is H2S2O8.
- Identify the elements: We have hydrogen (H), sulfur (S), and oxygen (O).
- Find the ratio of atoms:
- There are 2 hydrogen atoms, 2 sulfur atoms, and 8 oxygen atoms.
- Simplify the ratio:
- The ratio of hydrogen to sulfur to oxygen is 2:2:8.
- To simplify, divide all numbers by their GCD, which is 2.
- The simplified ratio is 1:1:4.
- Empirical formula: The empirical formula is HSO4.
Thus, the empirical formula of H2S2O8 is HSO4.
Explanation:
The molecular formula represents the actual number of atoms in a molecule, while the empirical formula represents the simplest whole-number ratio of those atoms. To obtain the empirical formula, we divide the subscripts in the molecular formula by their GCD. This simplification allows chemists to understand the basic stoichiometric relationship between the elements in a compound.
