a. In general is there any difference between R and S, and + and -? between d- and l-, and + and -?

b. Discuss the validity of the following statements:

        1. A mixture of (+)- and (--)-carvone can be separated by column chromatography on silica gel using hexanes-acetone as elution.

        2. In general, column chromatography on silica gel is run with a series of solvents of increasing polarity.

        3. Carvone is more polar than limonene.

c. Which compound, limonene or carvone, do you expct would elute first from the silica gel column? Which one would have shorter retention time on the GC? Briefly justify your answer.

True or False:

A. When atoms bond covalently energy is released

B. All the carbon to carbon bonds in benzene are the same.

C. A mole of NH3 and a mole of H2O weigh the same.

D. ice is denser than liquid water.

E. In organic compounds C atoms have 4 covalent bonds.

F. Water is a nonpolar compound.

G. Diamond, graphite, and fullerene are all forms of carbon.

H. All spontaneous chemical reactions are exothermic.

I. C4H8 is a saturated compound

J. When liquid water freezes heat is liberated.

1) Calculate the enthalpy of reaction (ΔHrxn) for the following reaction:

Fe2O3(s) + 3 CO(g) → 2 Fe(s) + 3 CO2(g)

Given: 4 Fe(s) + 3 O2(g) → 2 Fe2O3(s) ΔH = –1648 kJ 2 CO2(g) → 2 CO(g) + O2(g) ΔH = +565.4 kJ

2) Use standard enthalpies of formation to calculate the standard enthalpy of reaction for the following reaction:

2 H2S(g) + 3 O2(g) → 2 H2O(l) + 2 SO2(g) ΔH∘rxn

For the eight reactions done in test tubes, explain your observations in terms of mechanism (SN1 or SN2) , expected intermediates (carbocation or a single step conversion) and product. When they react with Sodium iodine in acetone and Silver nitrate in ethanol. 1. 1-Cholorbutane 2. 1-bromobutane 3. 2-Chlorobutane 4. 2- Chloro-2-Methyl Propane 5. Bromobutane 6. 2-Bromobutane 7. 2-Bromo-2-Metylpropane 8. 1-Chloro-2-Methyl Propane

2. A piece of Al(s) at 98°C is placed in 66g of H2O at 25°C. The Aluminum cools and after equilibrium the final temperature of Aluminum and water is 30°C. What was the mass of the aluminum? Cs(H2O)= 4.184J/(g°C)

Cs(Al)= 0.90J/(g.°C)

___ g

Amphetamine (C9H13N) is a weak base with a pKb of 4.2.

Calculate the pH of a solution containing an amphetamine concentration of 230 mg/L .

a) Which of the following reagents would oxidize Fe to Fe2 , but not Ag to Ag?

Ca, Co, Br^-, Ca²⁺, Co²⁺,Br₂

b) Which of the following reagents would oxidize Cu to Cu2 , but not Cl– to Cl2?

Br^-, Ca, Ca²⁺, Co²⁺, Br₂, Co

a) Predict in which direction the following reactions will proceed. Justify your answers briefly.

I. HCl + NaF ---- HF + NaCl

II. AlBr3 + 3 NaF ---- AlF3 + 3 NaBr

III. Ti(OMe)4 + 2 TiBr2 ---- TiBr4 + 2 Ti(OMe)2

IV. SrS + HgO ---- SrO + HgS

V. [Pt(CN)4] 2- + 4 NaCl ---- [PtCl4] 2- + 4 NaCN

VI. CoCl2 + CdI2 ---- CoI2 + CdCl2

VII. [Ag(NH3)2]NO3 + 2 NaSCN ---- NaNO3 + Na[Ag(SCN)2] + 2 NH3

A student followed the procedure of this experiment to determine the percent NaOCl in a commercial bleaching solution that was found in the basement of an abandoned house. The student diluted 50.00 mL of commercial bleaching solution to 250 mL in a volumetric flask, and titrated a 20-mL aliquot of the diluted bleaching solution. The titration required 35.46 mL of 0.1052M Na2S2O3 solution. A faded price label on the gallon bottle read $0.79. The density of the bleaching solution was 1.10 g/mL

Calculate the mass of NaOCl present in the diluted bleaching solution titrated

At 1 atm, how many moles of CO2 are released by raising the temperature of 1 liter of water from 20?C to 25?C?

In his explanation of the threshold frequency in the photoelectric effect, Einstein reasoned that the absorbed photon must have the minimum energy required to dislodge an electron from the metal surface. This energy is called the work function () of that metal. What is the longest wavelength of radiation (in nm) that could cause the photoelectric effect in each of the following metals?

(a) Tungsten, = 7.16 10-19 J

__nm

(b) Tantalum, = 6.41 10-19 J

__nm

(c) Silver, = 7.59 10-19

__J

free energy changed also depends on concentration. for gases, how is G related to the pressure for gases? what are standard standard pressures for gases and standard concentrations for solutes? how do you calculate ∆G for a reaction at nonstandard conditions? the equation to determine ∆G at nonstandard conditions has Q in it: what is Q? S reaction is spontaneous as long as ∆G is neg; that is, reactions always proceed as long as the products have a lower free energy than the reactants. what is so special about equilibrium? why don't reactions move away from equilibrium?

Enzyme X is a highly pigmented protein that imparts the characteristic color to certain blue-green algae. It also facilitates a reaction necessary to the survival of this species; we can follow the kinetics of this reaction by measuring the conversion of Substance X to Substance Y at various times during purification.

Given a pure preparation of these algae, and the required supplies and equipment, devise and outline an empirical procedure for purifying Enzyme X.

What is a good indication of purity in your preparation?

The outline of steps to purify Enzyme X should include detail of what the technique is, why that technique is needed, and what the result will be. The reader needs to have enough information so as to be able to do the experiment. Treat the assignment as one that demonstrates your knowledge of biochemical techniques in protein purification.

As for the length of this assignment, you are describing a protocol; therefore, you need to provide the necessary information for the reader to be able to know how, why, and what, as well as the potential outcomes of the steps and the end result.

Describe a chemical test that could be used to distinguish between pent-1-ene and pentane.

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Explain, using equations, the following steps in the free-radical mechanism of the reaction of methane with chlorine.

•        Initiation

•        Propagation

•        Termination

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What is the difference between UV-vis fluorescence and UV absorption (please be detailed with your response and explain the correlation between the two as well as their distinct properties)?