4. The rate with which enzymes can transform a substrate varies from enzyme to enzyme, and sometimes substrate to substrate. a) How are competitive and uncompetitive reversible inhibition similar? How is their effect on rate different? b) Enzyme reaction rates drop off dramatically as temperatures pass 50 °C or so, and do not return to their previous rate when cooled. Explain the drop off in activity and the lack of return to the previously higher reaction rates after heating. c) Pepsin is an enzyme that participates in digestion in the stomach, whereas trypsin is an enzyme that participates in digestion in the small inestines. Pepsin has the highest turnover number at around pH 2, whereas trypsin has the highest turnover number around pH 8. Explain this difference.

Codeine (C18H12NO3) is a weak base, (pKb= 5.79). A solution of 5*10^-2M solution has a pH of 10. Calculate the [C18H22NO3], [C18H21NO3] and [OH-] at equilibruim.

Benzoic acid is a weak monoprotic acid occurring in most of berries. The acid dissociation constant of benzoic acid is 6.3 x 10-5. Find pH and percent of dissociation of 0.001 M solution of benzoic acid.

You want to convert 2-chloropentane(an alky halide) into 1-pentene (an alkene). Which of the following reagents would you choose? (A)NaOH/water (B)KOH/methanol

   (C)CH₃ONa/CH₃OH (D) (CH₃)₃COK/(CH₃)₃COH

1. Consider the S_N2 reaction of butyl bromide with hydroxide ion , Assuming no other changes, what effect on the reaction rate would result from simultaneously doubling the concentrations of both butyl bromide and hydroxyl ion  A. No effect (B)It would double the rate (C)it would increase the rate six times

(D) It would increase the rate four times.

5. Select the rate law for a second order reaction: (A) rate = k[RX] (B) rate = k[RX]²[OH^-]

(C) rate = k[RX][OH^-] (D) rate k[RX]²[OH^-]²

Describe the extraction of magnesium from seawater in the Dow process. Show all relevant equations involved in the process, starting with the precipitation of Mg2+ as Mg(OH)2(s) using CaO(s) until the electrolysis of molten MgCl2.

The data below was collected in an experiment to determine the solubility of sodium nitrate at 20 Celsius degree.

1. If 5.0000g of NaNO3 was used, calculate the solubility in units of g NaNO3/100g water at each saturation temperature. Show your first calculation. Complete the rest of the calculations and fill in the table.

2. Construct a graph of solubility as a function of saturation.

3. Determine the solubility of sodium nitrate at 20 Celsius degree from a graph.

4. Using the solubility from #3, calculate the percent by mass of the salt in a saturated solution at 20 Celsius degree.

5. If the density of a saturated solution of sodium nitrate at 20 Celsius degree is found to be 1.4g/mL, calculate the Molarity of the solution.

For each pair of elements and compounds listed below, discuss their similarities and/or differences in terms of physical and chemical properties.

(a) Boron (B) and silicon (Si)

(b) BeCl2 and MgCl2;

(c) Al2O3 and In2O3;

What is the pH of a 0.39 M solution of sodium oxalate, Na₂C₂O₄? Acid ionization constants for oxalic acid are K_a1 = 5.6 x 10^-2 and K_a2= 5.4 x 10^-5.

Draw the mechanism and label products and reactants for the synthesis of aniline to 4-Bromo-2-Chloroacetanilide:

Aniline + Acetic Anhydride --> Acetanilide + Acetic Acid

Acetanilide + Bromine --> 4-Bromoacetanilide

STEP 1: Hydrochloric Acid + Sodium Chlorate --> Chlorine + Water + Sodium Chloride

STEP 2: 4-Bromoacetanilide + Chlorine --> 4-Bromo-2-Chloroacetanilide

4-Bromo-2-Chloroacetanilide + Ethanol --> 4-Bromo-2-Chloroaniline + Ethyl Acetate

Show all lone pairs or formal charges.

Water Chemistry

Respond to the following questions: Consider the bonding and geometry of the water molecule.

A) How many bonds does Hydrogen typically form? How many bonds does Oxygen typically form?

B) What is the Chemical Formula for Water?

C) What type of bonds (ionic, covalent, and metallic) holds the atoms of the water molecule together?

D) Why is the water molecule a bent molecule?

E) What are some of the consequences of the water molecule being bent?

F) When water boils, what happens to the Hydrogen and Oxygen atoms within a water molecule?

G) Discuss a few things that you know about Water based upon your reading, activities, and personal experience. How much can you tell me about water?

Solutions of sulfuric acid and lead(II) acetate react to form solid lead(II) sulfate and a solution of acetic acid. 5.10 gg of sulfuric acid and 5.10 gg of lead(II) acetate are mixed.

A. Calculate the number of grams of sulfuric acid present in the mixture after the reaction is complete.

B. Calculate the number of grams of lead(II) acetate present in the mixture after the reaction is complete.

C. Calculate the number of grams of lead(II) sulfate present in the mixture after the reaction is complete.

D. Calculate the number of grams of acetic acid present in the mixture after the reaction is complete.

For the triprotic acid, H+glutamic acid, pK1=2.23, pK2=4.42 and pK3=9.95. If one has 0.10L of a 1.0E-2 M solution and titrates it with 0.255 L of a 1.0E-2 M KOH solution, what is the pH of the resulting solution?

The answer is 10.04. I just have no clue how to get there.

The Racah parameter B is 460 cm-1 in [Co(CN)6]3– and 615 cm-1 in [Co(NH3)6]3+. Consider the nature of bonding with the two ligands and explain the difference in the B value.