Question

An atmospheric chemist studying the pollutant SO2 places a mixture of SO2 and O2 in a3.03 L container at 885.2 K and 2.65 atm. When the reaction occurs, gaseous SO3 forms, and the pressure falls to 1.17 atm. How many moles of SO3 form?

Answer 1

Answer:

Given,

To determine the SO3 moles

Let us consider the reaction which is given as follows

2SO₃ + O₂ ----> 2 SO_{3 gaseous form}

_{From the reaction we can say that,}

2 moles of SO2 reacts with one mole of oxygen to give 2 moles of SO2. that is 2 moles of SO2 produces 2 moles of SO3.

Now,

2SO₃ +    O₂ ---->    2 SO₃

initial moles x                  y                           0      Total moles =   (x+y)

after reaaction         0                 y-x                        x        total moles = y

   Thus before reaction occurs,

Consider,

PV = nRT

So number of moles (n) = PV/RT

Substitute the known values in above formula

n = 2.65 atmx3.03L/( 0.0821L.atmx 885.2K)

n = 0.110485 moles

After reaction,

Here now P = 1.17 atm

number of moles n = PV/RT = 1.17atmx 3.03L / 0.0821 x 885.2

= 0.04878 moles

Now,

y= 0.04878 &

x + y = 0.110485 moles

Hence,

Moles of SO2 reacted = moles of SO3 formed = 0.110485 - 0.04878

Therefor moles of SO3 formed = 0.061705 moles