W(KNO3) W(N) (NH4NO3)= 35% W(N)CA(NO3) W(N) (NH4)2 SO4

It looks like you're dealing with a classroom board that includes several chemical compounds and their nitrogen content. Here's a breakdown: 1. **KNO3 (Potassium Nitrate)**: Calculate the weight percentage of nitrogen (W(N)) in potassium nitrate by using the formula: \[ W(N) = \left(\frac{\text{Atomic weight of N}}{\text{Molecular weight of KNO3}}\right) \times 100 \] 2. **NH4NO3 (Ammonium Nitrate)**: The weight percentage of nitrogen is given as 35%. 3. **Ca(NO3)2 (Calcium Nitrate)**: Similarly, calculate the weight percentage of nitrogen. \[ W(N) = \left(\frac{2 \times \text{Atomic weight of N}}{\text{Molecular weight of Ca(NO3)2}}\right) \times 100 \] 4. **(NH4)2SO4 (Ammonium Sulfate)**: Calculate the weight percentage of nitrogen. \[ W(N) = \left(\frac{2 \times \text{Atomic weight of N}}{\text{Molecular weight of (NH4)2SO4}}\right) \times 100 \] To find the atomic weights, use the periodic table: - Nitrogen (N) = 14.01 g/mol - Potassium (K) = 39.10 g/mol - Oxygen (O) = 16.00 g/mol - Calcium (Ca) = 40.08 g/mol - Sulfur (S) = 32.07 g/mol - Hydrogen (H) = 1.01 g/mol Calculate the molecular weight by summing the atomic weights of each element in the compound and use these to find the percentages.