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 of a compound, we need to simplify the molecular formula by dividing the number of atoms of each element by the greatest common divisor (GCD) of those numbers. Let’s work through both molecular formulas you’ve provided.
1. For B2Cl4:
- The molecular formula shows that there are 2 boron (B) atoms and 4 chlorine (Cl) atoms.
- To find the empirical formula, we divide both subscripts by their GCD, which is 2. 22=1(for boron)\frac{2}{2} = 1 \quad \text{(for boron)}22=1(for boron) 42=2(for chlorine)\frac{4}{2} = 2 \quad \text{(for chlorine)}24=2(for chlorine)
- The empirical formula is BCl2.
2. For H2S2O8:
- The molecular formula shows that there are 2 hydrogen (H) atoms, 2 sulfur (S) atoms, and 8 oxygen (O) atoms.
- The GCD of 2, 2, and 8 is 2. 22=1(for hydrogen)\frac{2}{2} = 1 \quad \text{(for hydrogen)}22=1(for hydrogen) 22=1(for sulfur)\frac{2}{2} = 1 \quad \text{(for sulfur)}22=1(for sulfur) 82=4(for oxygen)\frac{8}{2} = 4 \quad \text{(for oxygen)}28=4(for oxygen)
- The empirical formula is HSO4.
Explanation:
The empirical formula represents the simplest whole-number ratio of atoms in a compound. By dividing each element’s atom count by the greatest common divisor (GCD), we reduce the molecular formula to its simplest form. In the case of B2Cl4, the ratio of boron to chlorine is reduced from 2:4 to 1:2, resulting in the empirical formula BCl2. Similarly, for H2S2O8, the ratio of hydrogen to sulfur to oxygen is reduced from 2:2:8 to 1:1:4, giving the empirical formula HSO4.
Thus, empirical formulas help us understand the simplest composition of compounds, which can be particularly useful in stoichiometric calculations.
