BEER's LAW                  A = 2 – log (% T) {Eqn # 1}               A = Constant x [Absorbing Molecule] {Eqn # 2}

Hi, I need help with the following Calculations for my Lab Report. The professor only gaves us these two Equations to solve them but I don't know how to start it or what to plug in. If you can please help me out. Thank you in advance. My Raw Data from Lab is below with the questions. Also on the very bottom is the information for the procedure and the concentration amounts.

CALCULATIONS

1. The proportionality constant in Beer's Law

In Solution 1, the concentration of iron (Fe3+) is so large that it is assumed, that the equilibrium has
COMPLETELY SHIFTED TO THE RIGHT. This means that the concentration of SCN– is zero, and the
concentration of the complex-ion (FeSCN2+) is equal to the initial concentration of the SCN–.

If ….A = Beer’s Law Constant x [FeSCN2+],

Re-arranging…. Beer’s Law Constant = A / [FeSCN2+]

2. Calculating the equilibrium concentration of FeSCN2+

Use the calculated Beer's Law Constant from solution 1, and the calculated absorbance of Solutions 2, 3,
and 4, to calculate the equilibrium concentrations of the FeSCN2+ in each solution.

3. Calculating the equilibrium constant, K

Use ICE tables to set-up the equilibrium expression and calculate the K of the complex-ion in solutions 2,
3, and 4.

RAW DATA FROM My LAB

Solution #1     Transmission = 10.5       Absorbance = 0.98

Solution #2     Trans. = 18         Absorbance =    0.75

Solution #3     Trans. = 34         Absrobance = 0.48

Solution #4     Trans. = 57        Absorbance = 0.25

Dilute nitric acid (NO3):                              0.50 M

Potassium Thiocianate (KSCN) sol’n:    0.00050 M

Ferric nitrate solutions (Fe(NO3)3):    0.050 M, 0.020 M, 0.0080 M, 0.0032 M

3. Use two small graduated cylinders to prepare the following four solutions. Use one cylinder for the ferric (Fe(NO3)3) solution, and one for the thiocyanate (KSCN) sol’n. Start with the least concentrated. Then calculate the initial concentrations of the KSCN and ferric ion solution in the new volume and record.

Solution 1: 4 mL of KSCN + 4 mL of the 0.050 M Fe(NO3)3

Solution 2: 4 mL of KSCN + 4 mL of the 0.020 M Fe(NO3)3

Solution 3: 4 mL of KSCN + 4 mL of the 0.0080 M Fe(NO3)3

Solution 4: 4 mL of KSCN + 4 mL of the 0.0032 M Fe(NO3)3

A bookstore at the Hartsfield-Jackson Airport in Atlanta sells reading materials (paperback books, newspapers, magazines) as well as snacks (peanuts, pretzels, candy, etc.). A point-of-sale terminal collects a variety of information about customer purchases. Shown below is a table showing the number of snack items and the number of items of reading material purchased by the most recent customers. Reading Material 0 1 2 Snacks 0 0 66 15 1 237 81 36 2 123 33 9 a. Using the data in the table construct an empirical discrete bivariate probability distribution for number of snack items and number of reading materials in a randomly selected customer purchase. What is the probability of a customer purchase consisting of one item of reading materials and two items of snack? (to 3 decimals) What is the probability of a customer purchasing one reading material item only? (to 3 decimals) Why is the probability ? The probability because the point of sale terminal is only used when makes a purchase. b. Show the marginal probability distribution for the number of snack items purchased. Compute the expected value and variance (if required enter negative values as negative numbers). (to 2 decimals) (to 2 decimals) (to 2 decimals) (to 4 decimals) (to 4 decimals) Expected Value (to 2 decimals) Variance (to 4 decimals) c. What is the expected value and variance for the number of reading materials purchased by a customer? Expected Value (to 2 decimals) Variance (to 4 decimals) d. Show the probability distribution for total number of items in a customer purchase. Compute its expected value and variance (if required enter negative values as negative numbers). (to 2 decimals) (to 2 decimals) (to 2 decimals) (to 4 decimals) (to 4 decimals) 1 2 3 4 Expected Value (to 2 decimals) Variance (to 4 decimals) e. Compute the covariance and correlation coefficient between and (if required enter negative values as negative numbers). (to 4 decimals) (to 4 decimals) What is the relationship, if any, between the number of reading materials and number of snacks purchased on a customer visit?

1. write a hypothesis for this chart?

3. Does the data in the table above support your hypothesis for this experiment? Be sure to use

    your data in explaining whether the hypothesis was supported or not.

4. Explain how the tooth length trait was influenced by natural selection in your experiment

How do you create a linear regression model with any intercept using Matrix operations. The following points are: (x0, x1, x2, y): (1, 2, 3, 15), (1, 4, 5, 23), (1, 1, 2, 8), and (1, 3, 5, 21).

Suppose the price of good 1 is ?1 = $6, the price of good 2 is ?2 = $12. Alice has ? = $120 available to spend on these two goods. Alice has utility function ?(?1, ?2) = √?1√?2. a) Write down the optimality condition that must hold at the optimal solution to Alice’s utility maximization problem. b) Find Alice’s marginal utilities for good 1 and for good 2 and find her marginal rate of substitution. c) Find Alice’s demand functions for her optimal quantities to consume of goods 1 and 2 (i.e., find formulas for her optimal values of ?1 and ?2 as functions of only prices and income). d) Given the prices and the money she has available, what is Alice’s optimal consumption of goods 1 and 2?

For problems 1 and 2, assume an activity coefficient of 1 for all substances and no effect of ionic strength. Eliminate terms in quadratic solutions for [H+ ] only if the weak acid is dissociated < 5%. Reported pKa values can vary depending on the conditions under which they were measured; therefore, in solving the following problems use the pKa values given with the problems.

1. What is the pH of 45 mM H3PO4? Phosphoric acid (H3PO4) is a triprotic acid; pKa1 = 2.12, pKa2 = 7.21, pKa3 = 12.32 Acetic acid pKa = 4.75

For problems 1 and 2, assume an activity coefficient of 1 for all substances and no effect of ionic strength. Eliminate terms in quadratic solutions for [H+] only if the weak acid is dissociated < 5%. Reported pKa values can vary depending on the conditions under which they were measured; therefore, in solving the following problems use the pKa values given with the problems.

1. a. What mM concentration of HBr gives a pH of 1.3?

What is the pH of 10 mM NaOH?

At equilibrium 0.1 M nitrous acid (HNO2) produces 7.4 mM NO2-. Calculate the pKa of HNO2.

b. What is the pH of 0.5 M benzoic acid? Benzoic acid Ka = 6.46 x 10-5 M

c. What is the pH of 45 mM H3PO4?

For c-f: Phosphoric acid (H3PO4) is a triprotic acid; pKa1 = 2.12, pKa2 = 7.21, pKa3 = 12.32

Acetic acid pKa = 4.75

d. What is the ratio of H2PO4- to H3PO4 at a pH of 3?

e. If 2 volumes of 18 mM KOH are mixed with 1 volume of 22.5 mM H3PO4, what will be the pH of the final mixture?

f. If 15 μmoles of acetic acid is generated in a 1.0 ml enzymatic reaction buffered by 50 mM Na-phosphate (pH 7.0), what will be the final pH of the reaction mixture?

Would the change in pH be smaller or larger if the reaction were buffered by 50 mM Na phosphate (pH 6.0)? Explain you answer; no calculations required.

2. a. Parietal cells control the concentration of HCl in the stomach by secreting H+ and Cl-. While fasting, they maintain stomach pH at 3.0. After a meal, they decrease stomach pH to 1.4. What is the fold-change in [H+] from fasting to after a meal?

b. For every H+ ion secreted into the stomach, parietal cells also secrete a HCO3- ion into blood plasma. HCO3- plays an important role in maintaining the pH of blood plasma (see textbook page 45 for equations). Patients with achlorhydria have impaired HCl secretion and thus have a loss of HCO3- in the blood. What will be the blood pH of a achlorhydria patient with half the normal concentration of HCO3- in the blood? Assume a constant CO2(d) of 1.2 mM and a normal HCO3- of 24 mM.

c. The pH of the stomach can influence the ionization of drugs such as Aspirin (aka acetylsalicylic acid or HAsp). Given that at equilibrium the pH of a 0.1 M Aspirin is 2.24, what is the pKa of Aspirin?

d. Using the pKa from c., what is the ratio of Asp- to HAsp in the stomach of the patient after a meal?

Would the ratio of Asp to HAsp increase, decrease or stay the same if the patient had fasted?

There exists a Charge A, that has a positive charge at position (1, -1, 2) in meters, and Charge B is another positive charge at (-1, 1, -2) in meters. Find the magnitude and direction of the electric field at points (0, 1, 0) and (0, 0, 0) written in vector form. b) What is the voltage at points (0, 1, 0) and (0, 0, 0)? Assume the charges are all STATIC (not moving). c) Add another negative charge, Charge C of   at (0, 0, 0). Find the force acting on Charge A from Charges B and C, find the magnitude and put its direction in magnitude form.

1. Enter the symbol of the zone axis for the planes (3 -2 -1 ) and ( -2 1 1).

2. The crystal wall belongs to two zones simultaneously (-1 0 1)and (-1 2 0). Give its Miller’s indicators.

3. If planes (412), (211) and (201) belong to a common zone, mark the axis symbol of this zone.

4. The lattice parameter of a regular crystal cell AgBr is ?0= 5,7745 ? . Calculate the interplanar distance dhkl for the lattice plane family : (200), (220), (311).

5. Calculate the interplanar distance d101 in the hexagonal crystal lattice of selenium, knowing that the network parameters ?0=4,3662 ? and ?0=4,9536 ? .

In a course, there are 2 exams consisting of 1 midexam and 1 final. In calculation of overall grades, 50 percent of midexam and final grades are taken. The grades of the midexam and the final are independent and normally distributed with means of 60 and 40, and with standard deviations of 18 and 24, respectively.

a) What is the probability a randomly selected student will get an overall grade that is larger than 80?

b) If the instructor wants 84.13 percent of students passing the course, what should be the value of passing grade (minimum overall grade which a student should score to pass the course)?