Question

Answer the questions about the following reaction below. The equilibrium constant for the decomposition of PCls at 250°C is 0.041 ΔH is positive; reactants and products are gases at 250°C. Refer to your textbook. 1. Is the reaction above exothermic or endothermic? 2. What happens to the concentrations of PCls and Cl if more PCls is added once the reaction reaches equilibrium? (increases, decreases) PC1s Cl2 3. What happens to the moles of PCIs, PCls and Cl in the container when the pressure at which the reaction is run is increased by decreasing the volume? PCIsPC Cl2 4. What happens to the concentrations of PCIs, PCl, and Ch when the temperature at whichth reaction is run is increased? PC15 PC13 C12 5. What happens to the concentrations of PCls and Ch if PCls is removed once the reaction reache equilibrium? PC13 C12 6. Does the value of the equilibrium constant, K, change in any above situations (2-5)? If so, which one(s)? Does it increase or decrease? #6 Chemical Equilibria Lab_Page 11 qf

Answer 1

1) if delta H positive then that is endothermic reaction.

2)when the concentration of Pcl3 increased the equilibrium shift towards left side because the system will tend to decresed the concentration of pcl3. So backward reaction favoured. So here PCl5 concentration increased and Cl2 concentration decreased.

3) if pressure increases then the reaction shifts to right side, then Pcl5- increased, pcl3- increased, cl2-increased

4) of temperature increses then reaction shifts to right side.

Pcl3- increased, cl2- increased

5) if reactant is removed then equilibrium will disturb .

6)no change in equilibrium constant " k "