21. The pH of a 0.120 M phenol solution is (Ka of phenol = 1.3 x 10-10):

a. 1.000

b. 10.81

c. 11.11

d. 5.40

e. 4.48

22. Which list gives equal concentrations of the following solutions in order of decreasing acidity?

HC₃H₅O₃ (K_a = 1.4 x 10^-4)       H₂O (K_a = 1.0 x 10^-14)              HOCl (K_a = 3.5 x 10^-8)

HCN (K_a = 4.9 x 10^-10)                HCl (K_a = 2 x 10⁶)

a. HC₃H₅O₃ > HCl > HOCl > HCN > H₂O

b. HCl > HC₃H₅O₃ > HOCl > HCN > H₂O

c. HCN > HOCl > HCl > HC₃H₅O₃ > H₂O

d. HCl > HC₃H₅O₃ > HOCl > H₂O > HCN

e. H₂O > HCN > HOCl > HC₃H₅O₃ > HCl

23. Which statement is true?

a. As the strength of a weak acid increases, the percent dissociation decreases

b. As the concentration of a weak acid increases, the percent dissociation increases.

c. As the strength of a weak acid decreases, the percent dissociation increases.

d. The percent dissociation of a weak acid is independent of the identity of the weak    

      acid.

e. As the value of K_a increases, the percent dissociation increases.

25. Which of the following salts will form a basic solution?

NaBr

Ca(NO₃)₂

NH₄Cl

NaCH₃CO₂

Al(ClO₄)₃

Chapter 12 Problem 3 (Excel functions needed)

Consider the project contained in Problem 7 in Chapter 11 (California Health Center).

a. Perform a sensitivity analysis to see how NPV is affected by changes in the number of procedures per day, average collection amount, and salvage value. Remember supplies vary with number of procedures.

b. Conduct a scenario analysis. Suppose that the hospital's staff concluded that the three most uncertain variables were number of procedures per day, average collection amount, and the equipment's salvage value. Furthermore, the following data were developed:

c. Finally, assume that California Health Center's average project has a coefficient of variation of NPV in the range of 1.0 - 2.0. (Hint: Coefficient of variation is defined as the standard deviation of NPV divided by the expected NPV.) The hospital adjusts for risk by adding or subtracting 3 percentage points to its 10 percent corporate cost of capital. After adjusting for differential risk, is the project still profitable?

d. What type of risk was measured and accounted for in Parts b. and c.? Should this be of concern to the hospital's managers?

A local manufacturing company builds two products on the same production line that consists of seven workstations. The times in hours and process stations are listed below. Process 1 Process 2 Process 3 Process 4 Process 5 Process 6 Process 7 Product A 0.25 1.75 1.0 1.5 1.5 2.75 0.25 Product B 0.25 0.75 0.5 1.5 0.5 0.75 0.25 The standard times for Product A is 9.0 hours and Product B is 4.5 hours. The company averages 22 units of Product A and 55 units of Product B per month. The company’s typical month is 22 days. Currently the production line is in a straight line configuration but management read a study that said cellular manufacturing is a better solution. Specifically they are interested in a U-shaped cell. They have approached you to setup the cellular work cell and determine how many workers will be needed. Before they implement this U-shaped cell, write a memo that explains the benefits of the cellular design over the current straight line layout and whether or not they should implement the cellular layout. Include how many employees are needed including the calculations, which processes would be worked by each employee, how many workstations are needed, and how the workstations should be arranged.

Calculating the Direct Labor Mix Variance

Mangia Pizza Company makes frozen pizzas that are sold through grocery stores. Mangia uses two types of direct labor: machine operators and packers. Mangia developed the following standard mix for spreading on premade pizza shells to produce 18 giant-size sausage pizzas.

Mangia's recent batch (designed to produce 300 pizzas) used 300 direct labor hours. Of the total, 120 were for machine operators, and the remaining 180 hours were for packers. The actual yield was 780 pizzas.

Required:

Instructions for parts 2 and 3: If a variance is zero, enter "0" and select "Not applicable" from the drop down box.

1. Calculate the standard mix (SM) in hours for machine operators and for packers.

2. Calculate the mix variance.

$   

3. Calculate the actual proportion of hours worked by machine operators and by packers. Enter the percentages as whole numbers.

Using the results, would the direction of the mix variance be favorable or unfavorable?

The total market value of Okefenokee Real Estate Company’s equity is $6 million, and the total value of its debt is $4 million. The treasurer estimates that the beta of the stock currently is 1.0 and that the expected risk premium on the market is 12%. The Treasury bill rate is 4%, and investors believe that Okefenokee's debt is essentialy free of default risk.

a. What is the required rate of return on Okefenokee stock? (Do not round intermediate calculations. Enter your answer as a whole percent.)

Required rate of return %

b. Estimate the WACC assuming a tax rate of 30%. (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places.)

WACC %

c. Estimate the discount rate for an expansion of the company’s present business. (Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places.)

Discount rate %

d. Suppose the company wants to diversify into the manufacture of rose-colored glasses. The beta of optical manufacturers with no debt outstanding is 1.5. What is the required rate of return on Okefenokee’s new venture? (You should assume that the risky project will not enable the firm to issue any additional debt.) (Do not round intermediate calculations. Enter your answer as a whole percent.)

Required rate of return %

Lactic acid is very good at penetrating the skin. Because of this, it is used in a number of products for skin care, such as exfoliating creams and chemical peels, and in formulations for transdermal delivery of medications, such as topical ointments and extended release patches for delivery through the skin. Lactic acid has a pKa of 3.86 in water at 25o C.

After graduation, you land your dream job at a small biotech firm specializing in novel antimicrobial agents. They have just developed a new drug, Poly-XSeption-L®, to help prevent antibiotic-resistant infections during local surgeries. Poly-XSeption-L® is to be applied to the skin at the site of the surgery in a liquid formulation containing lactic acid.

(a) The initial formulation being tested is a 1.0 wt% solution of Poly-XSeption-L® in a 0.015 M solution of aqueous lactic acid. Neglecting the effect of the antibiotic on the solution, what would you estimate the pH of this solution to be? State any assumptions you make.

(b) In clinical studies, it was found that the acidity of the initial formulation caused some problems with local irritation, and that Poly-XSeption-L® was not as effective below a pH of 4.2. It is proposed that sodium lactate be added to create a buffered solution with pH = 4.2. What concentration of sodium lactate should be used to achieve this pH?

Wolff Enterprises must consider several investment projects, A through E, using the capital asset pricing model (CAPM) and its graphical representation, the security market line (SML). Relevant information is presented in the following table

ITEM                            RATE OF RETURN                     BETA

Risk-free asset                          9%                                0.0

Market portfolio                       14%                              1.0

Project A                                  -                                   1.5

Project B                                   -                                   0.75

Project C                                   -                                   2.00

Project D                                  -                                   0.0

Project E                                   -                                   -0.50

1. Calculate (1) the required rate of return and (2) the risk premium for each project, given its level of nondiversifiable risk.
2. Use your findings in part a to draw the security market line (required rate of return relative to nondiversifiable risk)
3. Discuss the relative nondiversifiable risk of projects A through E.
4. Assume that recent economic events have caused investors to become less risk-averse, causing the market return to decline to 12%. Calculate the new required returns fcor assets A through E and draw the new security market line on the same graph you drew for b.
5. Compare your findings in parts a and b with those in part d. What conclusion can you draw about the impact of a decline in investor risk aversion on the required returns of risky assets?

An enzyme is discovered that catalyzes the chemical reaction

SAD --> <-- HAPPY

A team of motivated researchers set out to study the enzyme, which they call happyase. Under a constant enzyme concentration, [E] of 2.0 uM, they studied the relationship between substrate concentration [SAD] and reaction velocity V₀. Their data is shown below:

[SAD] (uM)                V₀ (uMs^-1)      

20                    3.4 x 10³

40                   5.4 x 10³

60                   6.6 x 10³

80                    7.4 x 10³

Can you determine K_cat and K_m from the above data?

2. While [E] remains 2.0 um and [SAD] = 12 uM, what would the reaction velocity V₀ be?

3. In a separate happyase experiment using [E] = 1.0 uM, the reaction velocity, V_0, is measured as 3.6 x 10³ uMs^-1. What is the [SAD] used in this experiment?

4.The researchers working on happyase discovered that the compound STRESS is a potent inhibitor of happyase. A kinetics study of happyase in the presence of         1 nM STRESS, gives the following data:

[SAD] (uM)                V₀ (uMs^-1)      

20                    1.7 x 10³

40                   2.7 x 10³

60                    3.3 x 10³               

80                    3.7 x 10³

Which class of inhibitors does STRESS belong to?