Question

Consider the elementary gas-phase reversible reaction A 3C Pure A enters at a temperature of 400 K and a pressure of 10 atm. At this temperature, KC 0.25(mol/dm3)2. Calculate the equilibrium conversion for each of the following situations:

Answer 1

• 39%

Step-by-step explanation:

The equilibrium equation is:

`A\rightleftharpoons 3C`

The initial concentration of A can be calculated from the ideal gas equation:

`pV=nRT\\\\n/v=p/(RT)\\\\C_A=(10atm)/(0.08206(atm-dm^3/K-mol)/times 400K)\\\\C_A=0.304mol/liter`

Determine the conversion of substance A to substance C using an ICE table and the Kc constant:

A ⇄ 3C

I 0.304 0

C - x + 3x

E 0.304 - x 3x

`K_c=0.25=((3x)^3)/((0.304-x))`

Solve for x:

You need to use a graphing calculator:

• 108x³ = 0.304 - x

• 108x³ + x - 0.304 = 0

• x ≈ 0.1195 mol/liter

Then:

`C_A=0.304mol/liter-0.1195mol/liter=0.1845mol/liter\\\\C_C=3* 0.304mol/liter=0.912mol/liter`

The equilbrium conversion is:

`\% = [0.304mol/liter-0.1845mol/liter]/(0.304mol/liter)* 100`

`\% \approx 39\%`