Answer the following questions:

a). The heat of fusion of ice is 6.00 kJ/mol. Find the number of photons of wavelength = 6.27 10-6 m that must be absorbed to melt 3.00 g of ice

b). The energy required to ionize potassium is 419 kJ/mol. What minimum frequency of light is required to ionize potassium?

c). An X-ray photon of wavelength 0.920 nm strikes a surface. The emitted electron has a kinetic energy of 936 eV. What is the binding energy of the electron in kJ/mol? [KE = .5 mv2; 1 electron volt (eV) = 1.602 10-19 J]

Hexokinase catalyzes the first step of glycolysis, in which glucose is phosphorylated to form glucose-6-phosphate. Which of the following statements are accurate? Choose all that apply.

Hexokinase is found in the mitochondrial membrane.

Hexokinase consists of two domains, or lobes, that come together when glucose and the MgATP2� complex are bound.

Most kinases require the presence of a monovalent metal ion cofactor to prevent ATP hydrolysis.

The conformational shift that occurs when glucose, but not water, enters the active site prevents water from hydrolyzing ATP.

Hexokinase transfers the terminal phosphate of ATP to carbon 3 of glucose.

Hexokinase is a type of transferase that catalyzes the transfer of a phosphoryl group from ATP to a hexose.

I already answered the first three questions and put the answer down I just don't know how to answer the last question which asks to calculate K in the rate law?

A clock reaction is run at 20 ºC with several different mixtures of iodide, sodium bromate and acid, to form iodine. Thiosulfate is used to react with the iodine formed initially. Starch indicator is added to form a blue color when all the thiosulfate has been used up and the iodine concentration begins to rise. The following sets of mixtures are used.

Initial concentrations in reaction mixtures
Run number [I^-]      [BrO₃^-]      [H⁺]
1 0.002          0.008       0.02
2 0.002       0.016            0.02
3 0.004         0.008         0.02
4 0.002        0.008             0.04   
[S₂O₃^2- ] is equal to 0.0001M in each reaction mixture.
The rate law is :
  
Rate = k [ I^-]^a   [ BrO₃^-]^b   [H⁺]^c


Reaction time in run number 1 30
Reaction time in run number 2 30
Reaction time in run number 3 15
Reaction time in run number 4 30

Calculate the following
a in the rate law

a=1

A clock reaction is run at 20 ºC with several different mixtures of iodide, sodium bromate and acid, to form iodine. Thiosulfate is used to react with the iodine formed initially. Starch indicator is added to form a blue color when all the thiosulfate has been used up and the iodine concentration begins to rise. The following sets of mixtures are used.

Initial concentrations in reaction mixtures
Run number [I^-]      [BrO₃^-]      [H⁺]
1 0.002          0.008       0.02
2 0.002       0.016            0.02
3 0.004         0.008         0.02
4 0.002        0.008             0.04   
[S₂O₃^2- ] is equal to 0.0001M in each reaction mixture.
The rate law is :
  
Rate = k [ I^-]^a   [ BrO₃^-]^b   [H⁺]^c


Reaction time in run number 1 30
Reaction time in run number 2 30
Reaction time in run number 3 15
Reaction time in run number 4 30

Calculate the following
b in the rate law

b=0

A clock reaction is run at 20 ºC with several different mixtures of iodide, sodium bromate and acid, to form iodine. Thiosulfate is used to react with the iodine formed initially. Starch indicator is added to form a blue color when all the thiosulfate has been used up and the iodine concentration begins to rise. The following sets of mixtures are used.

Initial concentrations in reaction mixtures
Run number [I^-]      [BrO₃^-]      [H⁺]
1 0.002          0.008       0.02
2 0.002       0.016            0.02
3 0.004         0.008         0.02
4 0.002        0.008             0.04   
[S₂O₃^2- ] is equal to 0.0001M in each reaction mixture.
The rate law is :
  
Rate = k [ I^-]^a   [ BrO₃^-]^b   [H⁺]^c


Reaction time in run number 1 30
Reaction time in run number 2 30
Reaction time in run number 3 15
Reaction time in run number 4 30

Calculate the following
c in the rate law

C=0

If the rate law for the clock reaction is:

   
Rate = k [ I^-] [ BrO₃^-] [H⁺]

A clock reaction is run with the following initial concentrations:

[I^-]               [BrO₃^-]            [H⁺]                         [S₂O₃^2-]
0.002                   0.008                   0.02                          0.0001  

The reaction time is 28 seconds

Calculate k in the rate law:?

You are making a stock salt solution by diluting 0.7563g of salt to 500mL with water.

a) What is the analytical concentration (in mol/L) if the salt is sodium chloride?

b) What is the analytical concentration of the solution (in mol/L) if the salt is Mohr's Salt?

c) How would you prepare 0.5L of -2x10^-4 M and -4x10^-5 M solutions from your Mohr's stock solution? Round to reasonable aliquot sizes, keeping in mind common pipette volumes.

d) Convert the concentrations in c. to ppm. Assume the density of the solution is that of the pure solvent.

d)

At 800K, 2 mol of NO are mixed with 1 mol of O2. The reaction 2NO(g) + O2(g) <---> 2NO2(g) comes to equilibrium under a total pressure of 1 atm. Analysis of the system shows that 0.71 mol of oxygen are present at equilibrium.

Calculate the equilibrium constant for the reaction.

answers 0.64

(a) How many milliliters of 0.165 M HCl are needed to neutralize completely 25.0 mL of 0.101 M Ba(OH)2 solution? 30.6 Correct: Your answer is correct. ml (b) How many milliliters of 3.50 M H2SO4 are needed to neutralize 25.0 g of NaOH? Incorrect: Your answer is incorrect. mL (c) If 54.8 mL of BaCl2 solution is needed to precipitate all the sulfate in a 544 mg sample of Na2SO4 (forming BaSO4), what is the molarity of the solution? Incorrect: Your answer is incorrect. M (d) If 27.5 mL of 0.125 M HCl solution is needed to neutralize a solution of Ca(OH)2, how many grams of Ca(OH)2 must be in the solution? Incorrect: Your answer is incorrect. g

1-sec-butoxy-3-chloro-1-methylcyclohexane

a) Draw structure

b) Draw all possible stereoisomers with R/S designation and label them A,B, C, etc.

c) List the enantiomers:

d) List the diastereomers:

e) List the meso compounds:

Question 2

Tyrosine is a triprotic amino acid with pKa of 2.17, 9.19, and 10.47 The first proton is removed

from the carboxylic acid ( –COOH), the second from the protonated amine group (–NH3

+) . The

third, with a pKa of 10.47, is the phenolic proton (–OH) on the aromatic ring.

Tyrosine

a) What is the structure of the most protonated form of tyrosine in aqueous solution?

! "#$%!*!'(!)!

b) Write the three acid dissociation equilibria with the correct charge (use Tyr as shorthand

for the part of the molecule excluding the acidic protons, i.e. Tyr(charge), HTyr(charge),

H2Tyr(charge), H3Tyr(charge)).

c) Suppose we titrate a 0.100 M solution of tyrosine hydrochloride salt (often written

Tyr!HCl) with a 0.100 M solution of a strong base (NaOH). Calculate pH at the

following points:

i. initially,

ii. half way to the first,

iii. at the first,

iv. half way to the second,

v. at the second, and

vi. half way to the third equivalence points

d) Using your results calculated in (c) sketch an accurate titration curve.

e) Based on your sketch, identify which equivalence point(s) can be used to identify end

point with an indicator dye.

f) For part (e), indicate what the pKa (or range) of indicator dye should be to minimize

determinate titration error.

g) Write the general expressions for the mass balance and the charge balance for part (c).

. Mg2+ ions are present in seawater, and the metal is often prepared by "harvesting" these ions and converting them to neutral Mg metal. The average magnesium content of the oceans is about 1270 g Mg2+ per ton of seawater, and the density of seawater is about 1.02 g/mL. (Some additional unit conversion factors are given below.) 1 ton = 2000 pounds 1 gallon = 3.7854 L 454 g = 1 pound

(6 pts) (a). How many gallons of seawater would be required to supply 123 kg of magnesium?

(6 pts) (b). Use information from above to find the molarity of Mg2+ ions in seawater?

Determine how many micrograms of phosphorus are in the following solutions:

1. 0.02M KH₂PO₄

2. 0.3M KH₂PO₄

3. 0.5M KH₂PO₄

4. 0.8M  KH2PO4

5. 1M  KH2PO4

6. 1.3M KH₂PO₄

When 2.14 g of a nonelectrolyte solute is dissolved in water to make 165 mL of solution at 22 °C, the solution exerts an osmotic pressure of 821 torr.

Compute the volume of 0.20M silver nitrate needed to precipitate the chloride ion in a 0.60g sample of an unknown that is 45% chloride and the mass of the solid nitrate used to prepare such a solution.

Mercury ions (Hg2+2) can be removed from solution by precipitation with Cl−. Suppose that a solution contains aqueous Hg2(NO3)2.

Express your answer as a chemical equation. Identify all of the phases in your answer.

A)Write complete ionic equation to show the reaction of aqueous Hg2(NO3)2 with aqueous sodium chloride to form solid Hg2Cl2 and aqueous sodium nitrate.

B)Write net ionic equation to show the reaction of aqueous Hg2(NO3)2 with aqueous sodium chloride to form solid Hg2Cl2 and aqueous sodium nitrate.

1) Explain with halogens are deactivators, but ortho, para directors, instead of m directors, in an EAS reaction.

2) Draw the energy diagrams for the first step of an electrophilic aromatic substitution reactions of a monosubstituted benzene, when the substituent is an electron-withdrawing group (E), an electron-donating group (D), and a halogen (X), respectively.

You measure the pH of rainwater at 5.4. Calculate the partial pressure of carbon dioxide (assume only CO₂ is present).

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