Calculate the relative molecular masses of: Potassium chlorate
The Correct Answer and Explanation is:
To calculate the relative molecular mass (also called molecular weight) of potassium chlorate (KClO₃), we need to sum the atomic masses of all the atoms in one molecule of the compound.
Step-by-step calculation:
- Identify the elements in potassium chlorate (KClO₃):
- Potassium (K)
- Chlorine (Cl)
- Oxygen (O)
- Determine the atomic masses:
- Potassium (K) has an atomic mass of approximately 39.1 g/mol.
- Chlorine (Cl) has an atomic mass of approximately 35.5 g/mol.
- Oxygen (O) has an atomic mass of approximately 16.0 g/mol.
- Account for the number of atoms of each element in the formula:
- KClO₃ contains 1 atom of potassium (K),
- 1 atom of chlorine (Cl),
- 3 atoms of oxygen (O).
- Multiply the atomic masses by the number of atoms:
- Potassium: 1×39.1=39.1 g/mol1 \times 39.1 = 39.1 \, \text{g/mol}1×39.1=39.1g/mol
- Chlorine: 1×35.5=35.5 g/mol1 \times 35.5 = 35.5 \, \text{g/mol}1×35.5=35.5g/mol
- Oxygen: 3×16.0=48.0 g/mol3 \times 16.0 = 48.0 \, \text{g/mol}3×16.0=48.0g/mol
- Add them together to get the relative molecular mass: Molecular mass of KClO₃=39.1+35.5+48.0=122.6 g/mol\text{Molecular mass of KClO₃} = 39.1 + 35.5 + 48.0 = 122.6 \, \text{g/mol}Molecular mass of KClO₃=39.1+35.5+48.0=122.6g/mol
Conclusion:
The relative molecular mass of potassium chlorate (KClO₃) is 122.6 g/mol.
