Which statement is a reason that a cell's chemical reactions may NOT reach equilibrium? The cell wants to prevent the harmful effects of an accumulation of excess intermediates. The concentration of the product of the reaction is not changing over time. Within the cell, multiple reactions are linked. For example, the product of one reaction may be the reactant in a different reaction. The cell is only capable of microscopic reversibility. All of the answers are correct.

1. A process is spontaneous in the direction that moves it away from equilibrium toward equilibrium

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?

In a particular experiment, the equilibrium constant measured for the reaction, Cl2(g)+NO2(g)Cl2NO2(g), is 2.8. Based on this measurement, calculate AG° for this reaction. Calculate AG° using data from Appendix E at the back of the book and discuss the agreement between your two calculations.

Identify the first chemical step in the production of Portland cement. How is this reaction related to the chemistry that takes place in the carbonation of concrete?

For each of the changes listed will the rate of the following chemical reaction increase, decrease, or remain the same? Fe(s)+2HCl(aq)FeCl2(aq)+H2(g) a. the concentration of HCl is decreased b. the iron is ground into a powder c. a catalyst is added to the reaction mixture d. the temperature of the solution is decreased

12.102 A chemical engineer is working to optimize the production of acrylonitrile to be used in the manufacture of carbon fibers. The reaction being used is the combination of propene gas, ammonia, and oxygen. The reaction is normally carried out at moderately high temperatures so all species are in the gas phase. (a) Write the equilibrium constant expression for this reaction. (b) The boiling point of acrylonitrile is 77 °C, and that of propene is -48 °C. What would the equilibrium expression be if this reaction were carried out at room temperature? (c) What characteristic of this reaction might cause the engineer to desire carrying out this reaction at room temperature?

For the generalized chemical reaction A(g)+B(g)C(g)+D(g) determine whether the concentration of D in an equilibrium mixture will (1) increase, (2) decrease, or (3) not change when each of the following changes is effected. a. concentration of A is increased b. concentration of B is decreased c. concentration of C is increased d. concentration of C is decreased

Adenosine triphosphate, ATP, is used as a free-energy source by biological cells. (See the essay on page 624.) ATP hydrolyzes in the presence of enzymes to give ADP: ATP(aq)+H2O(l)ADP(aq)+H2PO4(aq);G=30.5kJ/molat25C Consider a hypothetical biochemical reaction of molecule A to give molecule B: A(aq)B(aq);G=+15.0kJ/molat25C Calculate the ratio [B]/[A] at 25C at equilibrium. Now consider this reaction coupled to the reaction for the hydrolysis of ATP: A(aq)+ATP(aq)+H2O(l)B(aq)+ADP(aq)+H2PO4(aq) If a cell maintains a high ratio of ATP to ADP and H2PO4 by continuously making ATP, the conversion of A to B can be made highly spontaneous. A characteristic value of this ratio is [ATP][ADP][H2PO4]=500 Calculate the ratio [B][A] in this case and compare it with the uncoupled reaction. Compared with the uncoupled reaction, how much larger is this ratio when coupled to the hydrolysis of ATP?

For the generalized chemical reaction A(g)+B(g)C(g)+D(g) determine whether the concentration of A in an equilibrium mixture will (1) increase, (2) decrease, or (3) not change when each of the following changes is effected. a. concentration of B is increased b. concentration of C is decreased c. concentration of D is increased d. concentration of D is decreased