Answer:
0.8524 moles have to be added
Explanation:
Step 1: Data given
An equilibrium mixture contains 0.350 mol of each of the products
Each product contains 0.200 moles
Volume = 1.00L
Step 2: The balanced equation
CO(g) + H2O(g) ⇆ CO2(g) + H2(g)
Step 3: Calculate Kc
Kc = [CO2][H2] / [CO][H2O]
Kc = [0.350][0.350]/[0.200][0.200]
Kc = 3.0625
Step 4: The initial number of moles
nCO2 = 0.200 moles = 0.200 M
nCO = 0.200 moles = 0.200 M
nCO2 = O.350 + n moles = 0.350 + n M
nH2 = 0.350 M
Step 5: the number of moles at the equilibrium
nCO2 = 0.200 moles + X = 0.300 mol
⇒ X = 0.100 moles
nCO = 0.200 moles + 0.100 moles = 0.300 moles
nCO2 = 0.350 + n -0.100 moles = 0.250 + n
nH2 = 0.350 -0.100 = 0.250 moles
Step 6: Calculate Kc
Kc = [CO2][H2] / [CO][H2O]
3.0625 = (0.250 + n)(0.250) / (0.300)(0.300)
0.2756 = (0.250 + n)(0.250)
1.1024 = 0.250+n
n = 0.8524 moles
0.8524 moles have to be added