4. If I use a catalyst,

a. how will it change the reaction?

b. if it is an equilibrium reaction, how will it change the equilibrium constant?

5. What happens to the equilibrium if I add some of the product to the beaker where the reaction is happening? How does the equilibrium shift? Is it gone forever?

For the diprotic weak acid H2A, Ka1 = 2.2 × 10-6 and Ka2 = 8.4 × 10-9. What is the pH of a 0.0600 M solution of H2A? What are the equilibrium concentrations of H2A and A2– in this solution?

1a)  From the volume of titrant added, calculate the moles of vitamin C for each titration. Show a sample calculation for trial 1, and then just state the final results for the calculation of trials 2 and 3. Use 5 digits in all intermediate values and report the final value to the appropriate number of significant figures.

Trial 1

Trial 2

Trial 3

b) From the results of question 1, calculate the average value for the number of moles of vitamin C titrated. Report the final value to the appropriate number of significant figures.

c) Calculate the precision for the mole values used to calculate the average in question 2.

Data table:

KlO3 concentration= 0.002012 M

Part (a) The cyclopentadienyl anion (C5H5 - ) is commonly used aromatic ligand. The secular equations for describing the interactions of the five unhybridized p orbitals lead to a matrix of the form:

( ?11 − ??11 ?12 − ??12 ?13 − ??13 ?14 − ??14 ?15 − ??15
?21 − ??21 ?22 − ??22 ?23 − ??23 ?24 − ??24 ?25 − ??25
?31 − ??31 ?32 − ??32 ?33 − ??33 ?34 − ??34 ?35 − ??35
?41 − ??41 ?42 − ??42 ?43 − ??43 ?44 − ??44 ?45 − ??45
?51 − ??51 ?52 − ??42 ?53 − ??53 ?54 − ??54 ?55 − ??55)

where ??? is the Hamiltonian integral for orbitals ? and ? and ??? is the overlap integral for orbitals ? and ?. This matrix can be simplified using the approximations of Hückel molecular orbital (MO) theory, which involves two constants ? and ?.

(i) Explain the approximations of Hückel MO theory in terms of ??? and ???, and define ? and ?.

(ii) Re-write the above matrix applying these assumptions. [You may write this matrix (and only the matrix) on paper and copy and paste and image of it into your word document if you wish.] (iii) Briefly explain (without performing any calculations) how this matrix is used to determine the energies and coefficients of the MOs.

How does the absorption capacity of the regenerated activated carbon compare to that original activated carbon? Explain why there is a difference.

Solve an equilibrium problem (using an ICE table) to calculate the pH of each solution:

Express your answer using two decimal places

a) a solution that is 0.170 mol L⁻¹ in HC₂H₃O₂ and 0.125 mol L⁻¹ in CH₃COOK

b) a solution that is 0.205 mol L⁻¹ in CH₃NH₂ and 0.100 mol L⁻¹ in CH₃NH₃Br

Complete, balance, and write the net ionic equations for the following reactions: Also classify each reaction, giving its type.

Al (s) + Fe(NO₃)_2(aq) → Type of reaction __________

Na₃PO_{4 (aq)} + Ba(NO₃)_{2 (aq)} → Type of reaction __________

H₂SO₃ (aq) + KOH_(aq) → Type of reaction __________

NH₄Cl + NaOH → Type of reaction __________

You think you have a receptor with three identical and independent ligand binding sites that came about from trimerization of monomeric receptors. If you knew what the signal was for binding to one monomer, would a binding titration be able to prove that the trimer is being formed? What are some techniques to prove it exists as a trimer in solution (i.e. that its molecular weight is three times the monomer)?

2.Calculate the pH of a solution made by mixing 50.00 mL of 0.100 M KCN with 4.33 mL of 0.425 M strong acid HCl. HCN pKa = 9.21.

In the article Tooth Decay: A Delicate Balance, we learn that tooth decay occurs when the equilibrium between mineralization and demineralization becomes unsteady, according to this equation:

Ca5(PO4)3(OH) ↔ 5 Ca2+ + 3 PO43- + OH-

When a tooth decays, which way do we expect the equilibrium to lie? What does that tell us about the magnitude of K for this reaction?

Mustard gas, used in chemical warfare in World War I, has been found to be an effective agent in the chemotherapy of Hodgkin's disease. It can be produced according to the following reaction: SCL2(g)+2C2H4(g)<-->S(CH2CH2Cl)2(g). An evacuated 5.0L flask at 20.0C is filled with 0.258 mol SCl2 and 0.592 mol C2H4. After equilibrium is established, 0.0349 mol of mustard gas is present. 1. What is the partial pressure of each gas at equilibrium? 2. What is K at 20C?

Post-lab Question #1: While both NaBH4 and LiAlH4 can both be used toreduce ketones and aldehydes, the procedure that you followed in lab wouldnot result in the fluorenol product if NaBH4 were simply replaced with LiAlH4. a) Explain why. b) What change to the procedure would have to be made to use LiAlH4 tosuccessfully reduce fluorenone to fluorenol?

Post-lab Question #2: NaBH4 is not capable of reducing esters since estersare less reactive than ketones. Explain structurally why this is the case.

Post-lab Question #3: In lab, NaBH4 was kept in a dessicator to avoidprolonged contact with water in the atmosphere. This is done since waterwill react with NaBH4. Write the balanced equation for the decomposition of NaBH4 by water.

Post-lab Question #4: It is found that a bottle of NaBH4 in a lab contains 70% NaBH4 by mass as a significant portion has reacted with atmosphericwater as described in question 3 above. What is the minimum that astudent should weigh out to fully reduce 3.18 g of fluorenone?

Show the math of ATP production/ consumption in glycolysis.