Question

If 8 g of ammonium hydroxide is completely decomposed by the reaction below in a closed container with a total volume of 5.oo L and at 25 degrees C, what will be the partial pressure of the amonia gas liberated, in atmospheres? Assume the volume of the liquid is negligible.
NH4OH(aq)=H2O(1)+NH3(g)

Answer 1

Answer:

1 atm

Explanation:

Step 1: Write the balanced equation

NH₄OH(aq) ⇒ H₂O(l) + NH₃(g)

Step 2: Calculate the moles corresponding to 8 g of NH₄OH

The molar mass of NH₄OH is 35.04 g/mol.

8 g × 1 mol/35.04 g = 0.2 mol

Step 3: Calculate the moles of NH₃ formed from 0.2 moles of NH₄OH

The molar ratio of NH₄OH to NH₃ is 1:1. The moles of NH₃ formed are 1/1 × 0.2 mol = 0.2 mol

Step 4: Calculate the pressure of 0.2 moles of NH₃ in a container of 5.00 L at 25 °C (298 K)

We will use the ideal gas equation.

P × V = n × R × T

P = n × R × T / V

P = 0.2 mol × 0.0821 atm.L/mol.K × 298 K / 5.00 L

P = 1 atm