Question

Use the following information and the balanced reaction below to answer thefollowing questions:4 NH3 + 3 02 --> 2 N₂ + 6H₂OIf 71.9 L of ammonia react with an excess of oxygen gas, find the mass of waterformed.Show your work

Answer 1

Step-by-step explanation

Given:

Balanced equation: 4NH3 + 302 --> 2N₂ + 6H₂O

Volume of NH3 = 71.9 g

O2 is in excess

At STP : Pressure = 1 atm

: Temperature = 273 K

We know the R constant = 0.082 L.atm/K.mol

Required: Find the mass of water

Solution

Step 1: Find the moles of NH3 using the ideal gas law

PV = nRT where P is the pressure, V is the volume, n is the moles, R is the gas constant and T is the temperature.

n = PV/RT

n = (1 atm x 71.9L)/(0.082 L.atm/K.mol x 273 K)

n = 3.212 mol

Step 2: Find the moles of water using stoichiometry

The moles of H2O = 3.212 mol x (6/4)

= 4.818 mol

Step 3: Calculate the mass of H2O

m = n x M where m is the mass, n is the moles and M is the molar mass

m = 4.818 mol x 18,01528 g/mol

m = 75.32 g

Answer

Mass of water = 75.32 g