Question

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 ammonium phosphate is produced by the reaction of 2.5g of ammonia

Answer 1

7.3 g (NH₄)₃PO₄

Step-by-step explanation:

The balanced equation for the reaction is:

H₃PO₄ + 3 NH₃ ----> (NH₄)₃PO₄

To find the mass of ammonium phosphate ((NH₄)₃PO₄) produced, you need to (1) convert grams NH₃ to moles NH₃ (via the molar mass from the periodic table), then (2) convert moles NH₃ to moles (NH₄)₃PO₄ (via mole-to-mole ratio from balanced equation), and then (3) convert moles (NH₄)₃PO₄ to grams (NH₄)₃PO₄ (via molar mass from periodic table). Make sure to arrange the ratios/conversions in a way that allows for the cancellation of units. The final answer should have 2 sig figs because the given value (2.5 grams) has 2 sig figs.

Molar Mass (NH₃): 14.01 g/mol + 3(1.008 g/mol)

Molar Mass (NH₃): 17.034 g/mol

Molar Mass ((NH₄)₃PO₄):

3(14.01 g/mol) + 12(1.008 g/mol) + 30.97 g/mol + 4(16.00 g/mol)

Molar Mass ((NH₄)₃PO₄): 149.096 g/mol

2.5 g NH₃ 1 mole NH₃ 1 mole (NH₄)₃PO₄ 149.096 g
--------------- x -------------------- x --------------------------- x --------------------------
17.034 g 3 moles NH₃ 1 mole (NH₄)₃PO₄

= 7.3 g (NH₄)₃PO₄