What is the molecular mass of KMnO4?
Understand the Problem
The question is asking for the molecular mass of potassium permanganate (KMnO4). This involves calculating the mass by adding the atomic masses of each element in the compound based on its chemical formula.
Answer
158.04 u
Answer for screen readers
The molecular mass of potassium permanganate (KMnO4) is 158.04 u
Steps to Solve
- Write the chemical formula and identify the elements
The chemical formula of potassium permanganate is $KMnO_4$. It consists of potassium (K), manganese (Mn), and oxygen (O).
- Find the atomic masses of each element
Look up the atomic masses from the periodic table:
- Potassium (K): 39.10 u
- Manganese (Mn): 54.94 u
- Oxygen (O): 16.00 u
- Multiply the atomic masses by the number of each element in the formula
Calculate the total atomic mass for each element in the compound:
- Potassium: $1 \times 39.10 = 39.10$ u
- Manganese: $1 \times 54.94 = 54.94$ u
- Oxygen: $4 \times 16.00 = 64.00$ u
- Add the masses to find the total molecular mass
Sum the atomic masses to find the total molecular mass of $KMnO_4$:
$$39.10 + 54.94 + 64.00 = 158.04$$
The molecular mass of potassium permanganate (KMnO_4) is 158.04 u.
The molecular mass of potassium permanganate (KMnO4) is 158.04 u
More Information
The unit 'u' stands for atomic mass unit (amu), which is used to express atomic and molecular weights.
Tips
A common mistake is to forget to multiply the atomic mass of oxygen by 4, since there are four oxygen atoms in the molecule. Always double-check the chemical formula to ensure the correct number of each type of atom is used in your calculations.
