# As Level Chemistry-chemical equilibrium

Worksheet A            Equilibrium Calculations
Solve each problem and show all of your work.
1.         SO3(g)         +     H2O(g)                ⇄    H2SO4(l)
At equilibrium [SO3] = 0.400M             [H2O] = 0.480M                  [H2SO4] = 0.600M
Calculate the value of the equilibrium constant.
2.         At equilibrium at 100oC, a 2.0L flask contains:
0.075 mol of PCl5             0.050 mol of H2O               0.750 mol 0f HCl           0.500 mol of POCl3
Calculate the Keq for the reaction:
PCl5 (s) + H2O (g) ⇄ 2HCl (g) + POCl3 (g)
3.         Keq= 798 at 25oC for the reaction:  2SO2 (g)   +  O2 (g) ⇄  2SO3 (g).
In a particular mixture at equilibrium, [SO2]= 4.20 M and [SO3]=11.0M. Calculate the equilibrium [O2] in this mixture at 25oC.
4.         Consider the following equilibrium:
2SO2 (g) + O2 (g) ⇄ 2SO3 (g)
0.600 moles of SO2 and 0.600 moles of O2 are present in a 4.00 L flask at equilibrium at 100oC. If the Keq = 680, calculate the SO3 concentration at 100oC.
5.         Consider the following equilibrium:
2 NO2(g)           ⇄        N2O4(g)
2.00 moles of NO2 and1.60 moles of N2O4 are present in a 4.00 L flask at equilibrium at 20oC. Calculate the Keq at 20oC .
6.         2 SO3(g)           ⇄        2 SO2(g)           +          O2(g)
4.00 moles of SO2 and 5.00 moles O2 are present in a 2.00 L container at 100oC and are at equilibrium. Calculate the equilibrium concentration    of SO3 and the number of moles SO3 present if the Keq = 1.47  x  10-3.
7.         If  at equilibrium [H2] = 0.200M and [I2] = 0.200M and Keq=55.6 at 250oC, calculate the equilibrium concentration of HI.
H2 (g) + I2 (g) ⇄ 2HI (g)
8.         1.60 moles CO, 1.60 moles H2O, 4.00 moles CO2, 4.00moles H2 are found in a 8.00L container at 690oC at equilibrium.
CO (g) + H2O (g) ⇄ CO2 (g) + H2 (g)
Calculate the value of the equilibrium constant.