Chem 110 Reci – Week 9 – Equilibrium
1. Fill in the table below which refers to the following reaction and calculate Kc.
2NO(g) + Br2(g) ßà 2NOBr(g)
NO / Br2 / NOBrI / 2.5 / 5.0 / 1.0
C
E / 2.0
2. 5.0 mol NH3 are introduced into a 5.0 L reactor vessel in which it partially dissociates at high temperatures.
2NH3(g) ßà 3H2(g) + N2(g)
At equilibrium, 1.0 mol NH3 remains. Calculate Kc.
3. Sodium carbonate can be made by heating sodium bicarbonate:
2NaHCO3(s) ßà Na2CO3(s) + CO2(g) + H2O(g) Kp = 0.23 atm at 100oC
If a sample of NaHCO3 is placed in an evacuated flask and allowed to achieve equilibrium at 100oC, what will be the total gas pressure?
4. At 400oC, Kc = 64 for the equilibrium:
H2(g) + I2(g) ßà 2HI(g).
If 3.00 mol H2 and 3.00 mol I2 are introduced into an empty 4.0 L vessel, find the equilibrium concentration of HI at 400oC.
The following two questions refer to the reaction below:
C2H5OH + CH3COOH ßà CH3COOC2H5 + H2O
5. When two moles each of ethanol and acetic acid are allowed to react at 100oC in a sealed container, equilibrium is established when two thirds of a mole of each of the reactants remains. Calculate the equilibrium constant.
6. If 5.00 moles each of acetic acid and ethanol are allowed to react in a 1.00 liter sealed container at 100oC until equilibrium is reached, how many moles of the ester and water are produced and how many moles of ethanol and acetic acid remain? Use the equilibrium constant found in the previous problem.
7. For the synthesis of ammonia
N2(g) + 3H2(g) ßà 2NH3(g)
The equilibrium constant Kc at 375oC is 1.2. Starting with [H2] = 0.76 M, [N2] = 0.60 M, and [NH3] = 0.48, which gases will have increased in concentration and which will have decreased in concentration when the mixture comes to equilibrium? What are the concentrations?