To determine the percentage composition of hydrochloric acid (HCl), we first need to find the molar mass of the compound.
Hydrochloric acid consists of hydrogen (H) and chlorine (Cl) atoms. The atomic masses of these elements from the periodic table are approximately:
- Hydrogen (H): 1.01 g/mol
- Chlorine (Cl): 35.45 g/mol
Next, we calculate the molar mass of HCl:
Molar Mass of HCl = Atomic Mass of H + Atomic Mass of Cl
Molar Mass of HCl = 1.01 g/mol + 35.45 g/mol = 36.46 g/mol
Now, to find the percentage composition of each element in HCl, we use the following formula:
Percentage of Element = (Mass of Element / Molar Mass of Compound) × 100%
1. For Hydrogen:
Percentage of H = (1.01 g/mol / 36.46 g/mol) × 100% ≈ 2.77%
2. For Chlorine:
Percentage of Cl = (35.45 g/mol / 36.46 g/mol) × 100% ≈ 97.23%
In conclusion, the percentage composition of HCl is approximately 2.77% hydrogen and 97.23% chlorine.