CHM 2046C Module 10 Sample Exam Answers

Part J: Vocabulary / More Equilibrium Shifts Chapter 16 (10 points)

_Homogeneous Phase_ 1. If all the reactants and the products are in the same phase

(such as gases), then the we say the system is in

_______________equilibrium.

_Heterogenous Phase_ 2. If at least one of the reactants or one of the products is not in

the same phase, then we say the system is in

__________________ equilibrium.

_ Dynamic Equilibrium _ 3. The state where the concentrations of the reactants and the

products remain constant with time , it is said that the system has

reached a state of ___________equilibrium.

_ Reaction Quotient ___ 4. The __ ___ Q is obtained by by applying the law of mass

action using the initial concentrations of both the reactants and the

products instead of the equilibrium concentration so as to determine the

direction of the equilibrium shift.

_ Le Chatelier’s Principle _5. ___ __ states that if a change is imposed

on a system in equilibrium , the position of the equilibrium will shift in a

direction that tends to reduce that change.

Predict the effect on each of the following changes to the system on the direction of equilibrium:

a. Moves to the Right

b. Moves to the Left

c. Has no effect/does not move left or right

The combination of hydrogen gas and oxygen gas to give water vapor can be expressed by
2 H₂ (g) + O₂ (g) çè 2 H₂O (g)

_Right A________6. Water is removed as it is being generated

_Right A________ 7. Additional H₂ is added

_Right A________ 8. The system is cooled (assuming the reaction is exothermic)

_Left B_________ 9. The container is made larger

_Right A________10. Nitrogen gas (which does not react with neither reactants nor products) is injected into the cylinder causing a change in the pressure.