Ammonium phosphate NH43PO4 is an important ingredient in many fertilizers. It can be made by reacting phosphoric acid H3PO4 with ammonia NH3 . What mass of phosphoric acid is consumed by the reaction of 4.10g of ammonia?
The Correct Answer and Explanation is:
To find the mass of phosphoric acid (H₃PO₄) consumed in the reaction with 4.10 g of ammonia (NH₃), we start by writing the balanced chemical equation:
H₃PO₄ + 3NH₃ → (NH₄)₃PO₄
Step-by-Step Calculation:
- Determine the molar mass of NH₃:
- N: 14.01 g/mol
- H: 1.008 g/mol × 3 = 3.024 g/mol
- Molar mass of NH₃ = 14.01 + 3.024 = 17.034 g/mol
- Calculate moles of NH₃:
Moles of NH₃=4.10 g17.034 g/mol≈0.2407 mol\text{Moles of NH₃} = \frac{4.10\ \text{g}}{17.034\ \text{g/mol}} \approx 0.2407\ \text{mol}
- Use the molar ratio from the balanced equation:
From the reaction:
- 1 mol of H₃PO₄ reacts with 3 mol of NH₃
So, the number of moles of H₃PO₄ needed:
Moles of H₃PO₄=0.2407 mol NH₃3≈0.0802 mol\text{Moles of H₃PO₄} = \frac{0.2407\ \text{mol NH₃}}{3} \approx 0.0802\ \text{mol}
- Calculate the mass of H₃PO₄:
- H₃PO₄ molar mass:
- H: 1.008 × 3 = 3.024
- P: 30.97
- O: 16.00 × 4 = 64.00
- Total = 3.024 + 30.97 + 64.00 = 97.994 g/mol
Mass of H₃PO₄=0.0802 mol×97.994 g/mol≈7.86 g\text{Mass of H₃PO₄} = 0.0802\ \text{mol} × 97.994\ \text{g/mol} \approx 7.86\ \text{g}
✅ Final Answer:
7.86 grams of phosphoric acid (H₃PO₄) are consumed.
Explanation:
The reaction between phosphoric acid (H₃PO₄) and ammonia (NH₃) forms ammonium phosphate ((NH₄)₃PO₄), a key component in many fertilizers. This process is important in agriculture, where fertilizers are used to supply plants with essential nutrients like nitrogen and phosphorus. Understanding the stoichiometry of this reaction allows us to calculate how much of one reactant is needed to completely react with a given amount of another.
The chemical reaction is:
H₃PO₄ + 3NH₃ → (NH₄)₃PO₄
This balanced equation tells us that one mole of phosphoric acid reacts with three moles of ammonia. We begin by converting the given mass of ammonia (4.10 grams) into moles using its molar mass, which is 17.034 g/mol. This gives approximately 0.2407 moles of NH₃.
Next, we apply the mole ratio from the balanced equation. Since it takes three moles of ammonia to react with one mole of phosphoric acid, we divide the ammonia moles by three. This gives about 0.0802 moles of H₃PO₄ required.
Then, we convert these moles into grams using the molar mass of H₃PO₄ (97.994 g/mol). Multiplying gives approximately 7.86 grams of H₃PO₄.
This method demonstrates the core principle of stoichiometry: using balanced equations and molar relationships to predict the outcomes of chemical reactions. This type of calculation is critical in industrial applications like fertilizer production, where precise amounts of reactants must be mixed to maximize yield and minimize waste.
