Answer:
2.35
Explanation:
<em>A 1.00-L flask was filled with 2.00 moles of gaseous SO₂ and 2.00 moles of gaseous NO₂ and heated. After equilibrium was reached, it was found that 1.21 moles of gaseous NO was present. Assume that the reaction
</em>
<em>SO₂ + NO₂ ⇌ SO₃ + NO
</em>
<em>occurs under these conditions. Calculate the value of the equilibrium constant, K, for this reaction.</em>
<em />
Step 1: Calculate the molar concentrations
Since the reaction takes place in a 1.00 L flask, the molar concentrations are:
[SO₂]i = 2.00 M
[NO₂]i = 2.00 M
[NO]eq = 1.21 M
Step 2: Make an ICE chart
SO₂ + NO₂ ⇌ SO₃ + NO
I 2.00 2.00 0 0
C -x -x +x +x
E 2.00-x 2.00-x x x
Step 3: Calculate the concentrations at equilibrium
The concentration of NO at equilibrium is 1.21 M. Then, x = 1.21.
[SO₂]eq = 2.00-1.21 = 0.79 M
[NO₂]eq = 2.00-1.21 = 0.79 M
[SO₃]eq = x = 1.21 M
[NO]eq = x = 1.21 M
Step 4: Calculate the value of the equilibrium constant, K, for this reaction
K = [SO₃] × [NO]/[SO₂] × [NO₂]
K = 1.21²/0.79² = 2.35
