Given: \( \cdot 330.32 \mathrm{~g} \) potassium \( \cdot 135.17 \mathrm{~g} \) oxygen - 8.52 g hydrogen Wanted: percent composition by mass?

To determine the percent composition by mass of potassium (K), oxygen (O), and hydrogen (H) in the given mixture, follow these steps: ### 1. **Calculate the Total Mass** Add up the masses of all the elements: \[ \text{Total Mass} = \text{Mass of K} + \text{Mass of O} + \text{Mass of H} = 330.32\,\text{g} + 135.17\,\text{g} + 8.52\,\text{g} = 474.01\,\text{g} \] ### 2. **Calculate the Percent Composition** For each element, use the formula: \[ \text{Percent Composition} = \left( \frac{\text{Mass of the Element}}{\text{Total Mass}} \right) \times 100\% \] - **Potassium (K):** \[ \frac{330.32\,\text{g}}{474.01\,\text{g}} \times 100\% \approx 69.7\% \] - **Oxygen (O):** \[ \frac{135.17\,\text{g}}{474.01\,\text{g}} \times 100\% \approx 28.5\% \] - **Hydrogen (H):** \[ \frac{8.52\,\text{g}}{474.01\,\text{g}} \times 100\% \approx 1.8\% \] ### 3. **Final Percent Composition** - **Potassium (K):** **69.7%** - **Oxygen (O):** **28.5%** - **Hydrogen (H):** **1.8%** These percentages represent the composition of each element by mass in the given mixture.