Balance the following oxidation-reduction reactions using the half-reaction method.

a) S^2-(aq) + NO₃^-(aq) ---> S₈(s) + NO₂(g) acidic solution

b) MnO₄^-(aq) + I^-(aq) ---> MnO₂(s) + IO₃^-(aq) basic solution

c) Sb(s) + H₂SO₄(aq) ---> Sb₂(SO₄)₃(s) + SO₂(g) acidic solution

1) Sort the phrases pertaining to pure substances and mixtures as either true or false. Note: If any part of this question is answered incorrectly, a single red X will appear indicating that one or more of the phrases has been placed incorrectly.

a)pure substances cnnot be separated by physical means.

b) homogeneous mixtures have unifform properties throughout.

c) the components of homogeneous and heterogeneous mixtures cannot be separated.

d) components of a homogeneous mixture are visibly distinct.

e) heterogeneous mixtures contain more than one part, and each part has its own properties.

A 110.0 −mL buffer solution is 0.110 M in NH3 and 0.135 M in NH4Br.

Part A What mass of HCl could this buffer neutralize before the pH fell below 9.00? Express your answer using two significant figures.

m=?

Part B If the same volume of the buffer were 0.265 M in NH3 and 0.390 M in NH4Br, what mass of HCl could be handled before the pH fell below 9.00? Express your answer using two significant figures.

m=?

What is the difference between absorption and emission? Transmission and reflection?

When plotting a graph of A vs. B, what does it mean if one says that A is directly proportional to B? What would the graph look like?

NAD^+(aq)+2H^+(aq)+2e^- --> NADH(aq)+H^+(aq) E= -0.320V

Oaloacetate^2-(aq)+2H^+(aq)+2e^- --> malate^2-(aq) E= -0.166V

a. Calculate the standard potential for the following reaction: Oxaloacetate^2- (aq) +NADH(aq)+H^+(aq) --> malate-(aq)+NAD^+(aq)

b. Calculate the equilibrium constant for the reaction at 298K

The Na –glucose symport system of intestinal epithelial cells couples the \"downhill\" transport of two Na ions into the cell to the \"uphill\" transport of glucose, pumping glucose into the cell against its concentration gradient. If the Na concentration outside the cell ([Na ]out) is 163 mM and that inside the cell ([Na ]in) is 23.0 mM, and the cell potential is -51.0 mV (inside negative), calculate the maximum ratio of [glucose]in to [glucose]out that could theoretically be produced if the energy coupling were 100% efficient. Assume the temperature is 37 °C.

If the same volume of the buffer were 0.265 M in NH3 and 0.390 M in NH4Br, what mass of HCl could be handled before the pH fell below 9.00?

Two sig. figs.

m= ?

For a molecule of fluorous acid, the atoms are arranged as HOFO. (Note: In this oxyacid, the placement of fluorine is an exception to the rule of putting the more electronegative atom in a terminal position.) What is the formal charge on each of the atoms? Enter the formal charges in the same order as the atoms are listed. Express your answers as charges separated by comma. For example, a positive one charge would be written as +1.

Discuss the difference of the following sample preparation: (a) Liquid-liquid extraction (LLE) (b) Soxhlet extraction (c) Solid phase extraction (SPE) in terms of application, cost, extraction time, solvent usage.

1.) Determine the energy change (in Joules) associated with the transition from n=2 to n=4 in the Hydrogen atom.

2.) Calculate the wavelength (in nm) of the red line in the visible spectrum of excited H atoms using Bohr Theory.

3.) What is the energy (in Joules) of the X-ray radiation at 2.00x10^-10 m that are used for medical diagnosis?

4.) What is the binding energy of an electron in a photosensitive metal (in kj/mol) if the minimum frequency of light that can eject electrons from the metal is 6.3x10^14 Hz?

5.) How many photons are contained in a burst of yellow light (589nm) for a sodium lamp that contains 609 kJ of energy?

Which of the following hydrocarbons is expected to be the most reactive in ethanloic silver nitrate? Why? Write the organic product that you expect when your chosen substrate reacts.

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Draw the conjugate acid of compound A. Explain you choice.

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Provide a mechanism. Include all intermediates. Show all electron pushing.

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A sample contains a mixture of ²³⁹Pu and ²⁴⁰Pu in unknown proportions. The activity of the mixed sample was found to be 4.35 x 10⁷ dpm for a sample of 0.125 mg of Pu. Calculate the weight % of each Pu isotope present

53. Which of the following is an acid-base reaction? Select the best answer.

   (A). C(s) + O2(g)  CO2(g)

   (B). 2HClO4(aq) + Ca(OH)2(aq) 2H2O(l) + Ca(ClO4)2(aq)

   (C). Fe(s) + 2AgNO3(aq)  2Ag(s) + Fe(NO3)2(aq)

   (D). MgSO4(aq) + Ba(NO3)2(aq)  Mg(NO3)2(aq) + BaSO4(s)

   (E). All of the above are acid base reactions.

54. Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of K2S and Fe(NO3)2 are mixed.

   (A). Fe2+(aq) + S2-(aq)  FeS(s)

   (B). Fe2+(aq) + S2-(aq) + 2K+(aq) + 2NO3-(aq)  FeS(s) + 2K+(aq) + 2NO3-(aq)

   (C). K+(aq) + NO3-(aq)  KNO3(s)

   (D). Fe2+(aq) + S2-(aq) + 2K+(aq) + 2NO3-(aq)  Fe2+(aq) + S2-(aq) + 2KNO3(s)

55. According to the following reaction, what mass of PbCl2 can form from 422 mL of 0.110M KCl solution? Assume that there is excess Pb(NO3)2.

2KCl(aq) + Pb(NO3)2(aq)  PbCl2(s) + 2KNO3(aq) (balanced ?)

   (A). 7.19 g

   (B). 3.59 g

   (C). 6.45 g

   (D). 5.94 g

   (E). 1.30 g

56. When 10.00 moles of H2(g) react with 5.000 moles of O2(g) to form 10.00 moles of H2O(l) at 25°C and a constant pressure of 1.00 atm. If 683.0 kJ of heat are released during this reaction, and PΔV is equal to -37.00 kJ, then

   (A). ΔH° = -683.0 kJ and ΔE° = -646.0 kJ.

   (B). ΔH° = -683.0 kJ and ΔE° = -720.0 kJ.

   (C). ΔH° = +683.0 kJ and ΔE° = +720.0 kJ.

   (D). ΔH° = +683.0 kJ and ΔE° = +646.0 kJ.

57. Determine the molarity of a solution formed by dissolving 97.7 g LiBr in enough water to yield 750.0 mL of solution.

   (A). 0.130 M

   (B). 0.768 M

   (C). 2.30 M

   (D). 1.50 M

   (E). 1.18 M

59. Which one of the following compounds is(/are) soluble in water? Select all that apply.

   (A). Ca3(PO4)2

   (B). HgS

   (C). Ni(NO3)2

   (D). MgCO3

*** 8 Parts*** Write the equilibrium equation for the following reactions, and tell whether the reactants or products are favored in each case.

a) 2 CO(g) + O2(g) -------> 2 CO2(g) Keq = 2 x 10^11

b) Cl2O(g) + H2O(g) ------> 2 HOCl(g) Keq = 0.132

c) HF(aq) + H2O(l) ------> H3O+(aq) + F-(aq) Keq = 7.1 x 10^-4 

d) 3 O2(g) -----> 2 O3(g) Keq = 2.5 x 10^-29

e) S2(g) + 2 H2(g) -------> 2 H2S(g) Keq = 2.8 x 10^-21

f) CO(g) + 2 H2(g) -------> CH3OH(g) Keq = 10.5

g) Br2(g) + Cl2(g) ---------> 2 BrCl(g) Keq = 58.0

h) I2(g) -------> 2I(g) Keq = 6.8 x 10^-3

				Concentrations
	# of drops	# of drops	# of drops	Stock Solution	Stock Solution	Reaction (after mixing in well)	Reaction (after mixing in well)	Reaction Time (seconds)			Reaction Rate (sec-1)
Well #	HCl	H2O	Na2S2O3	HCl	Na2S2O3	HCl	Na2S2O3	Trial 1	Trial 2	Average
C1, D1	12	0	8	1M	0.3M	Yellow, odor	Yellow, odor	36	34	35	0.03
C2, D2	6	6	8	1M	0.3M	Yellow, odor	Yellow, odor	42	41	42.5	0.02
C3, D3	4	8	8	1M	0.3M	Yellow, odor	Yellow, odor	42	44	43	0.02

				Concentrations
	# of drops	# of drops	# of drops	Stock Solution	Stock Solution	Reaction (after mixing in well)	Reaction (after mixing in well)	Reaction Time (seconds)			Reaction Rate (sec-1)
Well #	HCl	H2O	Na2S2O3	HCl	Na2S2O3	HCl	Na2S2O3	Trial 1	Trial 2	Average
C4, D4	8	0	12	1M	0.3M	Yellow, odor	Yellow, odor	21	23	22	0.05
C5, D5	8	6	6	1M	0.3M	Yellow, odor	Yellow, odor	47	50	48.5	0.02
C6, D6	8	8	4	1M	0.3M	Yellow, odor	Yellow, odor	80	90	85	0.01

Determine the Reaction Order for HCl using calculations described in the Background section. Show your work. Note that your answer will probably not be an even whole number as it is in the examples, so round to the nearest whole number.

B.    Determine the Reaction Order for Na₂S₂O₃ using calculations described in the Background section. Show your work. Note that your answer will probably not be an even whole number as it is in the examples.