The deprotonation of acetic acid goes by the mechanism

CH₃COOH + H₂O ⇒ CH₃COO^– + H₃O⁺

Assume the pKa of acetic acid at 25°C is 4.76, and the forward rate at a pH of 4 is 102 s^–1.

(a) Calculate the forward and reverse rate constants for the reaction.

(b) Calculate the relaxation time if a 10^–2 M solution of solution of acetate in water at pH 6 is subjected to a temperature jump.

(c) Given reasonable estimates for molecular sizes, determine if the forward and/or the reverse reactions are likely to be diffusion limit.

a) Describe the differences between ionization energy, work function and electron affinity.

b) Show their location with respect to Evac on a band diagram.

The density of a gas is 1.76g/L at 1 atm and 10 °C. What is its density at 1.5 atm and 20 °C?

A. 4.65g/L

B. 3.23g/L

C. 1.52g/L

D. 2.15g/L

E. 2.55g/L

For questions 13-14, use the information provided below from the experiment Identification of an Unknown. The molecular masses and reactions are provided for you.

NaHCO₃          KHCO₃                        Na₂CO₃                        K₂CO₃              NaCl                KCl          

84.01 g/mol     100.12 g/mol   105.99 g/mol   138.21 g/mol   58.44 g/mol     74.55g/mol

2 NaHCO₃ (s) à Na₂CO₃ (s) + H₂O (g) + CO₂ (g)                    (Reaction 1)

Na₂CO₃ (s) +2HCl (aq) à 2NaCl (s) + H₂O (l) + CO₂ (g)         (Reaction 2)

13.       Brad starts with 0.652 g of unknown. How much mass should he have after the first heating step if his unknown
            was NaHCO₃?

            A.        0.411 g Na₂CO₃

            B.         0.326 g Na₂CO₃

            C.         0.822 g Na₂CO₃

            D.        0.00402 g Na₂CO₃

14.       If Brad has a final mass of 0.270 g at the end of the experiment (after the 2^nd heating), what is his percent yield
            of the final salt? (Assuming he starts with 0.652 g of NaHCO₃).

            A.       40%

            B.         60%

            C.         80%

            D.        86%

15.       What is the concentration of chloride ions in 50.0 mL of a 5.25 M solution of barium chloride?

            A.        0.525 M Cl^-

            B.         1.05 M Cl^-

                C.         5.25 M Cl^-

            D.        10.5 M Cl^-

Aqueous Solutions

16.       Which of the following represents a correct precipitation reaction between sodium iodide and lead(IV) sulfate?

            A.        PbSO₄ (aq) + NaI(aq) à PbI (aq) + NaSO₄ (aq)

            B.         PbSO₄ (aq) + NaI(aq) à PbI (s) + NaSO₄ (aq)

            C.         Pb(SO₄)₂(aq) + NaI (aq) à PbI₂ (s) + Na₂SO₄ (aq)

            D.        Pb(SO₄)₂(aq) + NaI (aq) à PbI₂ (aq) + Na₂SO₄ (aq)

17.       How many of the following salts would not form a precipitate in an aqueous solution?

A.       one

B.        two

C.         three

D.        four

18.       What type of reaction is the following?           CaCO₃ + heat à CaO + CO₂

            A.        Combination

            B.         Decomposition

            C.         Single Replacement

            D.        Combustion

19.       Calculate the amount of copper recovered from an 85% yield if the theoretical yield is 0.25 g

            A.        21 g

            B.         3.4 g

            C.         0.21 g

            D.        0.34 g

20.       Which of the following chemical species is the oxidizing agent in the reaction below?

Cu (s) + 4 HNO₃ (aq) → Cu(NO₃)₂ (aq) + 2 NO₂ (g) + 2 H₂O (l)

A.       Cu (s)

B.        HNO₃ (aq)

C.        Cu(NO₃)₂ (aq)

D.       NO₂ (g)

An unknown amount of riboflavin (100 tablets) was dissolved in 1 liter of water, one milliliter of the solution obtained was diluted to one liter. The measured fluorescence of the resulting solution was 42 units. A pattern containing 9.05 mg / liter of riboflavin gave a reading of 32 units. What is the average amount of milligrams of riboflavin in each tablet?

The equilibrium constants of the reactions

FeO(s) + CO(g) = Fe(s) + CO2; K1

FeO (s) + H2(g) = Fe(s) + H2O (g) ; K2

temp (oC) 600 700 800 900 1000

-------------------------------------------------------------

K1 0.900 0.673 0.535 0.453 0.396

K2 0.332 0.422 0.499 0.594 0.668

Calculate the equilibrium constant of the reaction

CO(g) + H2O(g) = CO2 (g) + H2(g)

at the above temperature Also calculate the heat of the reaction.

Are the following compounds acidic, basic, or neutral?

1. barium nitrate

2. sodium chloride

3. potassium nitrite

4. iron III chloride

5. sucrose

6. magnesium carbonate

7. lithium sulfite

8. naphthalene

9. potassium permanganate

10. lead II chloride

11. copper II bromide

12. calcium sulfate

1. Answer any three of the following parts (a) - (d). (a) The hydrolysis of a compound A-B in a dilute aqueous solution proceeds in one elementary step: A-B + H2O → A-OH + H-B (i) Describe the order of this reaction. (ii) Outline the differential and the integrated rate laws for this reaction. (iii) Calculate the reaction rate constant if the concentration of A-B at time 10 s was 0.1 mol L-1 and at time 1000 s was 0.001 mol L-1 .

Experiment #2: An experiment run found that the two enantiomers of Isoflurane do not act the same as anesthetics, in that it took a smaller amount of one to produce the same anesthetic effect as the other. What is a chiral receptor? What roles do chiral receptors play in biological systems? Does the fact that the two enantiomers of Isoflurane do not act the same support or disprove the hypothesis listed above? Explain your answer

Describe what is infrared (IR), nuclear magnetic resonance (NMR) and mass spectrometry (MS) and tell what chemical structure information can be determined from each.

Based on the structures of Isoflurane & Sevoflurane and what you have learned in Modules 5 and 8 this semester, would you expect these molecules to be hydrophilic or lipophilic? Explain your answer. (Make sure you base your answer on the structures alone – please note that your answer may or may not correlate with the experimentally determined result.)

What role do you think light plays in electron movement? Since light also functions as a wave, what is the relationship between light and electrons?

Assuming 100% dissociation, calculate the freezing point (TfTf) and boiling point (TbTb) of 1.39 m SnCl4(aq)1.39 m SnCl4(aq).

Colligative constants can be found in the chempendix.

Pure l-phenylalanine has a specific rotation of -35.1 degrees. What is the enantiomeric excess of a 10.0 g/mL solution of phenylalanine which when placed in a standard 1.00 dm cell and analyzed in a polarimeter rotates plane polarized light -31.6 degrees?

I. what is the energy content (GJ/ha) of willow at 55% moisture content, if it has a calorific value of 7MJ/kg and a yield of 22 tonnes/ha at 55% M.C?

II. if one tonne (1145 litres) equals 43GJ, what is the oil equivalent in litres of the willow per hectare?

III. if edenderry power station has an excess CO2 how many tonnes of willow at 55% M.C would be needed to clear the excess CO2? peat has a calorific value of 8GJ/tonne and yields 0.856 tonnes of CO2 per tonne burned

IV. what is the energy content of 10 ha of miscanthus at 20% M.C if the net calorific value is 13.7 MJ/kg at a yield of 12.5 tonne/ha?