Final answer:
The percentage composition of potassium nitrate is calculated by dividing the mass of each element by the total mass of the compound and then multiplying by 100. The composition is 38.66% potassium, 13.85% nitrogen, and 47.48% oxygen.
Step-by-step explanation:
The percentage composition of a compound refers to the percentage by mass of each element in the compound.
To find the percentage composition of potassium nitrate, which contains 78.2 g of potassium (K), 28.0 g of nitrogen (N), and 96.0 g of oxygen (O), you need to follow these steps:
- Calculate the total mass of the compound by adding the mass of each element: 78.2 g + 28.0 g + 96.0 g = 202.2 g.
- Calculate the percentage by mass for each element:
Potassium: (78.2 g / 202.2 g) × 100% = 38.66%
Nitrogen: (28.0 g / 202.2 g) × 100% = 13.85%
Oxygen: (96.0 g / 202.2 g) × 100% = 47.48%.
Therefore, the percentage composition of potassium nitrate is 38.66% potassium, 13.85% nitrogen, and 47.48% oxygen.