An open tubular column with a diameter of 193 um and a staionary phase thickness on the inner wall of 0.52 um passes unretained solute through in 61 s. A particular solute has a retention time of 453 s.

a) What is the partition coeffecient for this solute?

b) What fraction of time does this solute spend in the stationary phase?

9. Which of the following solutions has the greatest buffering capacity?

   [A] 0.243 M HF and 0.192 M NaF

   [B] 0.485 M HF and 0.383 M NaF

   [C] 0.970 M HF and 0.766 M NaF

   [D] 0.160 M HF and 0.126 M NaF  

   [E] They are all buffer solutions and would all have the same capacity.

   10. The Henderson-Hasselbalch equation is ________

   [A] pH = pK_a + log [acid]/[base]

   [B] [H⁺] = K_a + [base]/[acid]

   [C] pH = log [acid]/[base]

   [D] pH = pK_a - log [base]/[acid]

   [E] pH = pK_a + log [base]/[acid]

7. Calculate the pH of a solution prepared by dissolving 0.150 mol of benzoic acid and 0.300

   mol of sodium benzoate in water sufficient to yield 1.00 L of solution. The K_a of benzoic

   acid is 6.30 x 10^-5.

[A] 2.516 [B] 4.502 [C] 3.892 [D] 4.195 [E] 10.158

8. What change will be caused by addition of a small amount of HCl to a solution containing

fluoride ions and hydrogen fluoride?

[A] The fluoride ions will precipitate out of solution as its acid salt.

[B] The concentration of fluoride ion will decrease and the concentration of hydrogen

fluoride will increase.

[C] The concentration of hydronium ions will increase significantly

[D] The concentration of hydrogen fluoride will decrease and the concentration of

   fluoride ions will increase.

[E] The concentration of fluoride ions will increase as will the concentration of hydronium

   ions.

11. The addition of hydrofluoric acid and ________ to water produces a buffer solution

[A] HF [B] KI [C] NaF [D] NaBr [E] NaNO₃

(assume all thermodynamic quantities refer to the system, except where indicated)

Carbon dioxide sublimes at -78.5 degrees C at 1 bar pressure. When 1 mole of solid carbon dioxide is converted gas at 0 degrees C and 1 bar, which of the following quantities will be POSITIVE? CHOOSE ALL THAT APPLY: w, q, delta S, delta S_surr , delta S_total , delta G, delta H.

Consider an ionic compound, MX2 , composed of generic metal M and generic, gaseous halogen X . The enthalpy of formation of MX2 is Δ?∘f=−677 kJ/mol. The enthalpy of sublimation of M is Δ?sub=161 kJ/mol. The first and second ionization energies of M are IE1=647 kJ/mol and IE2=1377 kJ/mol. The electron affinity of X is Δ?EA=−339 kJ/mol. (Refer to the hint). The bond energy of X2 is BE=221 kJ/mol. Determine the lattice energy of MX2 . Δ?lattice= kJ/mol

I am asked to create a table of reducing potentials by setting ANY of the half-cell potential to 0V. Show calculations.

My half-cells and their Eocell is :

Ag+ + e- = Ag(s) 0.80V

Cu2+ + 2e- = Cu(s) 0.34V

Pb2+ + 2e- = Pb(s) -0.13V

Sn2+ + 2e- = Sn(s) -0.14V

Fe2+ + 2e- = Fe(s) -0.44V

Zn2+ + 2e- = Zn(s) -0.76V

Mg2+ + 2e- = Mg(s) -2.37V

Methanol (CH3OH) is made industrially in two steps from CO and H2. It is so cheap to make that it is being considered for use as a precursor to hydrocarbon fuels such as methane (CH4): Step 1. CO(g)+2H2(g)→CH3OH(l) ΔS∘ = -332J/K Step 2. CH3OH(l)→CH4(g)+1/2O2(g) ΔS∘ = 162J/K

a. Calculate an overall ΔG∘ for the formation of CH4 from CO and H2.

b. Calculate an overall ΔH∘ for the formation of CH4 from CO and H2.

c. Calculate an overall ΔS∘ for the formation of CH4 from CO and H2

d. is the overall reaction spontaneous?

e. If you were designing a production facility, would you plan on carrying out the reactions in separate steps or together?

f.

1. An electrochemical cell is based on the following two half-reactions:
Ox: Pb(s)→Pb2+(aq, 0.18 M )+2e−
Red: MnO−4(aq, 1.50 M )+4H+(aq, 1.8 M )+3e−→
MnO2(s)+2H2O(l) Compute the cell potential at 25 ∘C.

2.A concentration cell consists of two Sn/Sn2+ half-cells. The cell has a potential of 0.16 V at 25 ∘C.

What is the ratio of the Sn2+ concentrations in the two half-cells?

Express your answer using two significant figures.

3.Metal plating is done by passing current through a metal solution. For example, an item can become gold plated by attaching the item to a power source and submerging it into a Au3+ solution. The item itself serves as the cathode, at which the Au3+ions are reduced to Au(s). A piece of solid gold is used as the anode and is also connected to the power source, thus completing the circuit.

What mass of gold is produced when 8.80 A of current are passed through a gold solution for 18.0 min ?

Express your answer with the appropriate units.

A lead-acid battery uses a redox reaction in which lead(0) and lead(IV) are both converted to lead(II). This reaction is facilitated by the presence of sulfuric acid, H2SO4, as shown by the reaction

Pb+PbO2+2H2SO4→2PbSO4+2H2O

Suppose that a fully charged lead-acid battery contains 1.50 L of 5.00 M H2SO4. What will be the concentration of H2SO4 in the battery after 3.60 A of current is drawn from the battery for 6.00 hours ?

Consider the titration of 25.0 mL of 0.175 M cyanic acid, HCNO, with 0.250 M LiOH. The Ka of HCNO is 3.5 * 10^-4.

What is the volume of LIOH required to reach the equivalence point?
b. calculate the pH after the following volumes of LIOH have been added:
a. 0mL
b. 5.0 mL
c. 8.75 mL
d. 17.5 mL

10. How much methanol (CH₃OH, in grams) can be formed from 49.2 mg of hydrogen? Assume excess CO.

CO(g) + 2H₂(g) → CH₃OH(g)

-Consider the following balanced chemical equation: 2N₂H₄(g) + N₂O₄(g) → 3N₂(g) + 4H₂O(g)

a. How many moles of water form from 0.438 moles of N₂O₄?

b. How many moles of water form from 0.438 moles of N₂H₄?

c. How many moles of nitrogen form from 0.438 moles of N₂O₄?

d. How many moles of nitrogen form from 0.438 moles of N₂H₄?

What is the enthalpy of the following reactions? Use the appendix in your text book using heat formatino values.

1. SO3+ H2O-----H2SO4

2. 3K2O2+3H2O----6KOH+O3

3. Fe3O4+8HCL----2FeCl3+FeCl2+4H2O

1: Select all of factors that affect the rate of a chemical reaction:

Why is the region of the electromagnetic spectrum between 8 and 13 um known as the "atmospheric window"? Why are gases that absorb thermal IR in this range of particular concern? What are some of those gases?

A.) Write the equation which describes the reaction between crystal violet and hydroxide ion.

B.) A solution is prepared by mixing 25.0 mLs of 4.84*10^-6 M crystal violet solution with 20.0 mLs of 0.10 M NaOH solution and diluted to a final volume of 100.0 mLs. Determine the limiting reagent.

C.) After the reaction has gone to completion, calculate the concentration of all species in the reaction.

D.) How does the concentration of sodium hydroxide change over the course of the reaction?

E.) Explain your answer in question D in terms of the intial concentrations of reactants.

2,2,4-trimethylpentane

A) one retrosynthetic analysis

B) a reaction scheme showing each of the synthetic steps with starting materials, products, reagents and conditions

C) a paragraph or so describing the logic of a synthetic strategy and why it would be the most likely to give

the desired product.

D) References to any sources that were used.