Ammonium phosphate ((NH₄)₃PO₄) is an important ingredient in many fertilizers. It can be made by reacting phosphoric acid (H₃PO₄) with ammonia (NH₃). What mass of ammonium phosphate is produced by the reaction of 4.9 g phosphoric acid?



Answer :

To determine the mass of ammonium phosphate ((NH₄)₃PO₄) produced from 4.9 g of phosphoric acid (H₃PO₄), we first need to understand the balanced chemical equation for the reaction:

\[ \text{H₃PO₄} + 3 \text{NH₃} \rightarrow (NH₄)₃PO₄ \]

From the balanced equation, 1 mole of phosphoric acid (H₃PO₄) reacts with 3 moles of ammonia (NH₃) to produce 1 mole of ammonium phosphate ((NH₄)₃PO₄).

### Step-by-Step Calculation:

1. **Calculate the molar mass of phosphoric acid (H₃PO₄):**

  - Hydrogen (H): 1.01 g/mol × 3 = 3.03 g/mol

  - Phosphorus (P): 30.97 g/mol

  - Oxygen (O): 16.00 g/mol × 4 = 64.00 g/mol

  Total molar mass of H₃PO₄:

  \[ 3.03 \, \text{g/mol} + 30.97 \, \text{g/mol} + 64.00 \, \text{g/mol} = 98.00 \, \text{g/mol} \]

2. **Convert the given mass of phosphoric acid (H₃PO₄) to moles:**

  \[ \text{Moles of H₃PO₄} = \frac{\text{Mass}}{\text{Molar mass}} = \frac{4.9 \, \text{g}}{98.00 \, \text{g/mol}} = 0.05 \, \text{mol} \]

3. **Determine the moles of (NH₄)₃PO₄ produced:**

  - According to the balanced equation, 1 mole of H₃PO₄ produces 1 mole of (NH₄)₃PO₄.

  \[ \text{Moles of } (NH₄)₃PO₄ = 0.05 \, \text{mol} \]

4. **Calculate the mass of (NH₄)₃PO₄ produced:**

  - Now, calculate the mass using the molar mass of (NH₄)₃PO₄:

    - Ammonium (NH₄): 18.04 g/mol

    - Phosphorus (P): 30.97 g/mol

    - Oxygen (O): 16.00 g/mol × 4 = 64.00 g/mol

    Total molar mass of (NH₄)₃PO₄:

    \[ 18.04 \, \text{g/mol} + 30.97 \, \text{g/mol} + 64.00 \, \text{g/mol} = 113.01 \, \text{g/mol} \]

  \[ \text{Mass of } (NH₄)₃PO₄ = \text{Moles} \times \text{Molar mass} \]

  \[ \text{Mass of } (NH₄)₃PO₄ = 0.05 \, \text{mol} \times 113.01 \, \text{g/mol} = 5.65 \, \text{g} \]

### Conclusion:

Therefore, the mass of ammonium phosphate ((NH₄)₃PO₄) produced from 4.9 g of phosphoric acid (H₃PO₄) is **5.65 g**. This calculation considers the stoichiometry of the reaction and the molar masses of the substances involved.