The equilibrium constant Kc for the reaction 2NO (g) + O2 (g) ⇌2NO2 (g) is 6.9*105 at 500 K. A 5.0 L reaction vessel at 500 K was filled with 0.056 mol of NO, 1.0 mol of O2, and 0.90 mol of NO2. Part A What is the value of Qc?

Q = 1291.5

Explanation:

Step 1: Data given

Kc = 6.9 * 10^5 at 500 K

Volume = 5.0 L

Number of moles NO = 0.056 moles

Number of moles O2 = 1.0 moles

Number of moles NO2 = 0.90 moles

Step 2: The balanced equation

2NO (g) + O2 (g) ⇌ 2NO2 (g)

Step 3: Calculate the concentration

Concentration = moles / volume

[NO] = 0.056 moles / 5.0 L

[NO] = 0.0112 M

[O2] = 1.0 mol / 5.0L

[O2] = 0.2 M

[NO2] = 0.90 moles / 5.0L

[NO2] = 0.18 M

Step 4: Calculate Q

Q = [NO2]²/[NO]²[O2]

Q = [0.18²]/[ (0.0112²) (0.2) ]

Q = 1291.5