1.Which acid is the strongest?
  
H2X, Ka1 = 1×10-4
  
HX, Ka = 1×10-7
  
H2X, Ka1 = 1×10-5
  
HX, Ka = 1×10-5

2.Radioactive decay is a first-order rate process. The time required to reduce the activity from 800 counts/min to 100 counts/min for a radioactive sample with a half−life of 30 years is

3.This two-step mechanism has been suggested for a reaction:

N2O(g) + H2(g) N2(g) + H2O(g)

H2(g) + 2NO(g) N2O(g) + H2O(g)

3.Which choice correctly identifies an intermediate and a catalyst?

Intermediate Catalyst

N2O(g) NO(g)

none N2O(g)

N2O(g) none

H2O(g) none

1) What is the molarity of a 3.12 m solution of KCl dissolved in water, given that the solution has a density of 1.13 g/mL?

2)What is the concentration (ppm) of lead found in a water sample at the 3.29 x 10?5 M level?

3) A 14.0 M solution of concentrated nitric acid has 20.0 mL withdrawn from it. The 20.0 mL sample is then diluted until the total volume of the resulting solution is 2.50 L. What is the concentration of the dilute solution?

4) To prepare a Cd2+ standard, 0.280 g of cadmium metal is first dissolved in 50 mL of concentrated HCl, followed by dilution to 1.00 L. This solution is followed by another dilution that reduces the concentration by 100-fold. What is the concentration of the resulting solution?

please!!!!!!!

Two firms in the same industry sell their product at $10. The first firm has a total fixed cost of $100 and an average variable cost of $6; whereas the corresponding values for the second firm are $300 and $3.33 respectively. (a) Compute the sales elasticity of profit (ie. the percent change in total profit when sales increase by 1%) for the two firms at the point where each sells 60 units and also at the point where each sells 70 units. (b) What happens to this elasticity at the breakeven levels of output? (c) Comment on and interpret the elasticity values you computed above. The firm with the higher elasticity is said to be more highly leaveraged. What does this mean? How do you explain the difference between the elasticities of the two firms?

(THERMODYNAMICS) A vertical cylinder fitted with a frictionless piston contains 1.5 kg of H2O initially at 100 °C, 400 kPa.  If the volume of the system reaches 0.5 m3, the piston hits a set of stops and is restrained from further upward travel. The system is heated to 200 C. (Use saturated water tables, steam tables, and superheated tables as necessary)

a)   If the piston reaches the stops, determine the temperature and pressure when the piston first touches but exerts no force on the stops.  If the piston doesn’t reach the stops, find the final volume.  Clearly show how you determined whether or not the piston reaches the stops.

b)   Calculate the heat and work for the entire process.

c)   Show the entire process on a T-v and P-v diagram including the saturation curve.

A common breakfast cereal maker states that the sugar content of one of its popular cereal is approximately 36%.

A dataset by W. J. Braun gives the sugar percentages of 100 samples of 25g of the breakfast cereal, collected by using high performance liquid chromatogramphy.

The first 9 values are shown.

36.3, 33.2, 39, 37.3, 40.7, 38.4, 35.8, 36, 37.9…

We will be looking at the mean percentage of the sugar content of the sample in comparison to that of the stated value from the cereal maker.

Answer the following questions.

What is the population? (state and use the correct notation)

What is the sample?(state and use the correct notation)

What is the response variable? Is it categorical or quantitative?

What is the Sample statistic of interest? What’s the value of the sample statistic?(state and use the correct notation)

The following table shows one month’s results from a public health clinic’s testing for a new strain of flu during a pandemic that were confirmed the following month. Examine the results and answer the first four questions.

Patients With               Patients Without

                                                            New Flu                     New Flu

Patients Testing Positive             200                            100

Patients Testing Negative             50                             700

An anxious patient arrives at the clinic wanting to get tested. As the physician, you try to assuage their concerns and tell them that the test does a good job in identifying someone infected. “How well?” asks the distraught patient. What percentage chance does the test have in correctly identifying the patient as being truly sick or not sick?

Chance for test identifying someone truly sick:

Chance for test identifying someone truly well:

How much do wild mountain lions weigh? Adult wild mountain lions (18 months or older) captured and released for the first time in the San Andres Mountains gave the following weights (pounds): 66 100 133 122 60 64 Assume that the population of x values has an approximately normal distribution.

(a) Use a calculator with mean and sample standard deviation keys to find the sample mean weight x and sample standard deviation s. (Round your answers to one decimal place.)

x = _____ lb

s = _____ lb

(b) Find a 75% confidence interval for the population average weight μ of all adult mountain lions in the specified region. (Round your answers to one decimal place.)

lower limit = _______ lb

upper limit = _______ lb

Two loudspeakers 6.0 m apart are playing the same frequency. If you stand 10.0 m in front of the plane of the speakers, centered between them, you hear a sound of maximum intensity. As you walk parallel to the plane of the speakers, staying 10.0 m in front of them, you first hear a minimum of sound intensity when you are directly in front of one of the speakers.

PART A

What is the frequency of the sound? Assume a sound speed of 340 m/s.

PART B

If you stay 10.0 m directly in front of one of the speakers, for what other frequencies between 100 Hz and 600 Hz is there a minimum sound intensity at this point?

Express your answer numerically. If there is more than one answer, enter your answers in ascending order separated by commas.

A company had stock outstanding as follows during each of its first three years of operations: 4,000 shares of 8%, $100 par, cumulative preferred stock and 34,000 shares of $10 par common stock. The amounts distributed as dividends are presented below. Determine the total and per-share dividends for each class of stock for each year by completing the schedule. Round dividends per share to the nearest cent. Enter "0" if no dividends are paid.

Canadian Metal, Mining, and Petroleum Company are analyzing two projects for possible investment. Only one investment will be made. The first project is an oil? drilling project in Alberta at a cost of $500 million that will produce $100 million per year in Years 5 through 10 and $200 million per year in Years 11 through 20. The second project is an expansion of an aluminum smelter in Mapletree, Quebec, and will cost $500 million and will produce $87 million per year for Years 2 through 20. The cost of capital is 12 percent.

a. Which investment should be made?

b. If the oil?well project justifies an extra 4 percent premium over the normal cost of capital because of its riskiness and relative uncertainty of flows, does the investment decision change?