While ethanol (CH,CH,OH) is produced naturally by fermentation, e.g. in beer- and wine-making, industrially it is synthesized by reacting ethylene (CH,CH,) with water vapor at elevated temperatures. A chemical engineer studying this reaction fills a 25.0 L tank with 6.9 mol of ethylene gas and 11. mol of water vapor. When the mixture has come to equilibrium he determines that it contains 1.5 mol of ethylene gas and 5.6 mol of water vapor. The engineer then adds another 2.8 mol of water, and allows the mixture to come to equilibrium again. Calculate the moles of ethanol after equilibrium is reached the second time. Round your answer to 2 significant digits. I mol Ox10

How does equilibrium represent the balancing of opposing processes? Give an example of an “equilibrium” encountered in everyday life, showing how the processes involved oppose each other.

In Section 17.3 of your text, it is mentioned that equilibrium is reached in a closed system. What is meant by the term “closed system,” and why is it necessary for a system to reach equilibrium? Explain why equilibrium is not reached in an open system.

Explain that equilibrium is dynamic, and that at equilibrium the forward and backward reaction rates are equal.

Describe a nonchemical system that is in equilibrium, and explain how the principles of equilibrium apply to the system.

12.101 An engineer working on a design to extract petroleum from a deep thermal reservoir wishes to capture toxic hydrogen sulfide gases present by reaction with aqueous iron(II) nitrate to form solid iron(II) sulfide. (a) Write the chemical equation for this process, assuming that it reaches equilibrium. (b) What is the equilibrium constant expression for this system? (c) How can the process be manipulated so that it does not reach equilibrium, allowing the continuous removal of hydrogen sulfide?

5.2. What is the difference between a static equilibrium and a dynamic equilibrium? Give examples difference from the examples in the text. What is similar for the two types of equilibria?

In the figure, orange fish are placed in one aquarium and green fish in an adjoining aquarium. The two tanks are separated by a removable partition that is initially closed. (a) Describe what happens in the first few minutes after the partition is opened. (b) What would you expect to see several hours later? (c) How is this system analogous to dynamic chemical equilibrium?

Because calcium carbonate is a sink for CO32- in a lake, the student in Exercise 12.39 decides to go a step further and examine the equilibrium between carbonate ion and CaCOj. The reaction is Ca2+(aq) + COj2_(aq) ** CaCO,(s) The equilibrium constant for this reaction is 2.1 X 10*. If the initial calcium ion concentration is 0.02 AI and the carbonate concentration is 0.03 AI, what are the equilibrium concentrations of the ions? A student is simulating the carbonic acid—hydrogen carbonate equilibrium in a lake: H2COj(aq) H+(aq) + HCO}‘(aq) K = 4.4 X 10"7 She starts with 0.1000 AI carbonic acid. What are the concentrations of all species at equilibrium?

A 4.72-g sample of methanol (CH3OH) was placed in an otherwise empty 1.00-L flask and heated to 250.C to vaporize the methanol. Over time, the methanol vapor decomposed by the following reaction: CH3OH(g)CO(g)+2H2(g) After the system has reached equilibrium, a tiny hole is drilled in the side of the flask allowing gaseous compounds to effuse out of the flask. Measurements of the effusing gas show that it contains 33.0 times as much H2(g) as CH3OH(g). Calculate K for this reaction at 250.C.