A tray tower provides 10 equilibrium stages for stripping ammonia from a wastewater stream by
using a countercurrent air stream at 1 atm and 300 K. Assume that the inlet water concentration
is 0.2 mole% ammonia, the inlet air does not have ammonia, and 1 SCM (standard cubic meter)
of air is fed to the tower per kilogram of wastewater. Here the equilibrium curve is linear with
m= 1.414.
(a) Estimate the outlet molar concentration in the exit water.
(b) Assuming that the Murphree efficiency for the process is 65%, estimate the number of
real trays required for this process.
(c) How many real trays would be required to achieve ½ of the concentration in (a)?

pre lab question:

1. Assume for the moment that air consists of 80.00% nitrogen (N₂) and 20.00% oxygen (O₂) by volume. Use these figures and typical values for temperature and pressure (1.000 atm and 25.00°C) to calculate the density of air in g/L.

2. Explain how you will determine the mass of CO₂ gas in your flask.

3. This experiment will require you to know the volume of the air/gas present in your flask. How will you measure this volume?

4. If you are use a graduated cylinder with markings in increments of 0.2 mL to measure liquids, you should interpolate and record volume readings to the nearest what?

The amount of milk that the American Cookie Company sells in a given week is random. Suppose the milk sells for $2.00 per cup and it costs the store $1.50 per cup. The following describes the distribution of demand for milk in a one week period. There is a probability of 0.14 that the store will sell 100 cups of milk; there is a probability of 0.2 that the store will sell 150 cups of milk; there is a probability of 0.34 that the store will sell 170 cups of milk; otherwise, the store will sell 220 cups of milk. What is the expected number of cups of milk the store will sell in a given week? (please express your answer using 2 decimal places)

An economy has full-employment output of 6000. Government purchases are 1680. Desired consumption

and desired investment is given by

?? ? Cd= 3000-1500?+0.2?

?? ? Id= 500-3250?

where Y is output and r is the real interest rate.

a. (5 Points)What is the real interest rate that clears the goods market? Assume that output equals full employment

output.

b. (3 Points) Compute the amount of saving, investment and consumption in equilibrium.

c. (4 Points) What would happen to the equilibrium real interest rate if government purchases fell to

1600? Increase or decrease? Explain the intuition for the change. A diagram may be useful here.

A discrete random variable named X has the following pmf (probability mass function):

17a) Find P(X>6)

17b) What is the probability two independent observations of X will both equal 1?

17c) Find the population mean also known as E(X)= the expected value of

17d) Find the population variance of X with both the “regular” formula and “convenient”

formula

Make a table and show your work. You should get the same answer with both

formulas. Finally, find the standard deviation.

4. A) The probability that a student from a certain university has a cell phone is 0.2. So, the probability that the tenth student randomly interviewed at this university is the fifth with Cell phones is:

B) On a certain day, the second stage of the environmental contingency plan was implemented in the Mexico City. If there are 50 companies in the area that corresponds to a supervisor, of which 15 did not follow contingency guidelines, then the probability that 3 companies out of the 10 that are verified will not follow the guidelines is:

C)If the planes arriving at an airport follow a Poisson process with an average rate of 8 planes per hour. The probability of exactly 10 aircraft arriving in the next 2 hours is as close to:

A battery is constructed from these two half reactions:

            i.   VO²⁺   +   2 H⁺ + e-   → V³⁺   + H₂O        E^o = 0.337 V vs SHE

            ii.   TiF₆^{2 ̶}   +   4 e-   →   Ti(s) + 6 F ^̶                           E^o = ̶ 1.191 V

(a) (0.2 pt) Which half reaction is in the anode compartment?   Circle one:     vanadium rxn      titanium rxn

(b) Which half reaction is in the cathode compartment? Circle one:    vanadium rxn      titanium rxn

(c) Write the balanced chemical equation for the overall battery reaction.

(d) Show the shorthand notation for representing this particular battery:

(e) Calculate the E^o of the battery.

1.      If your firm calculates its Economic Capital due to Market Risk, Credit Risk, Operational Risk for the next 1 year as follows . . .    (10 points)

                  Market Risk           $323,000

                  Credit Risk             $515,000

                  Operational Risk    $ 83,270

         . . . what will be the firm's total Economic Capital . . .

         a.      If the correlations among the three types of capital are believed to be :

                  Market-Credit        0.4

                  Market-Operation 0.1

                  Credit-Operation   0.2

b.      If the correlations are all equal to 1.0:

d.      If you don't know the correlations, which measure is probably too high? which is                               probably too low? what might be a reasonable level to use?

A computer is shared by 2 users who send tasks to a computer remotely and work independently. At any minute, any connected user may disconnect with probability 0.5, and any disconnected user may connect with a new task with probability 0.2. Let X(t) be the number of concurrent users at time t (in minutes). This is a Markov chain with 3 states: 0, 1, and 2. The probability transition matrix can be calculated and it is Generate 10000 transitions of the Markov chain. What percent of times do you find your generated Markov chain in each of its 3 states? Write using R code.

Q4.(15) One random sample of the hours of one type of user watch TV per day was recorded: 2.9, 3.5, 3, 3.2, 3.3, 3.5, 3.3, 3, 3.5.

1.(5) Apply the backward empirical rule to check normality of the data, and conclude if any evidence of non-normality.

2.(5) Assume that the underlying population is normal. Find a two-sided 99% confidence interval for the the true population average hours

3.(5) Assume that population variance σ2=0.09σ2=0.09 and the bound on the error of estimation of 99% confident interval to be 0.2. Find the minimum sample size nn.