A solution is made by mixing 44.0 mL of ethanol, C 2 H 6 O , and 56.0 mL of water. Assuming ideal behavior, what is the vapor pressure of the solution at 20 ∘ C? The relevant values at 20 ∘ C are included in the table. Liquid Density (g/mL) Vapor Pressure, P ∘ (Torr) ethanol 0.789 43.9 water 0.998 17.5 vapor pressure:

Liquid	Density (g/mL)	Vapor Pressure, P∘P∘ (Torr)
ethanol	0.789	43.9
water	0.998	17.5

A 0.250-g sample of a magnesium-aluminum alloy dissolves completely in an excess of HCl(aq). When the liberated H2(g) is collected over water at 29 ∘C and 752 torr, the volume is found to be 303 mL . The vapor pressure of water at 29 ∘C is 30.0 torr. How many moles of H2 can be produced from x grams of Mg in magnesium-aluminum alloy? The molar mass ofMg is 24.31 g/mol. Express your answer in terms of x to four decimal places (i.e., 0.5000x).

The time and amount of decomposition of 0.056 M glucose at 140 degrees Celsius in an aqueous solution containing 0.35 N HCl were found to be

Time (Hr)	Glucose, remaining (Mole/Liter*10^2
0.5	5.52
2	5.31
3	5.18
4	5.02
6	4.78
8	4.52
10	4.31
12	4.11

What are the reaction order, the half-life, and the specific reaction rate of this decomposition? Can one unquestionably determine the order from the data given?

21. The pH of a 0.120 M phenol solution is (Ka of phenol = 1.3 x 10-10):

a. 1.000

b. 10.81

c. 11.11

d. 5.40

e. 4.48

22. Which list gives equal concentrations of the following solutions in order of decreasing acidity?

HC₃H₅O₃ (K_a = 1.4 x 10^-4)       H₂O (K_a = 1.0 x 10^-14)              HOCl (K_a = 3.5 x 10^-8)

HCN (K_a = 4.9 x 10^-10)                HCl (K_a = 2 x 10⁶)

a. HC₃H₅O₃ > HCl > HOCl > HCN > H₂O

b. HCl > HC₃H₅O₃ > HOCl > HCN > H₂O

c. HCN > HOCl > HCl > HC₃H₅O₃ > H₂O

d. HCl > HC₃H₅O₃ > HOCl > H₂O > HCN

e. H₂O > HCN > HOCl > HC₃H₅O₃ > HCl

23. Which statement is true?

a. As the strength of a weak acid increases, the percent dissociation decreases

b. As the concentration of a weak acid increases, the percent dissociation increases.

c. As the strength of a weak acid decreases, the percent dissociation increases.

d. The percent dissociation of a weak acid is independent of the identity of the weak    

      acid.

e. As the value of K_a increases, the percent dissociation increases.

25. Which of the following salts will form a basic solution?

NaBr

Ca(NO₃)₂

NH₄Cl

NaCH₃CO₂

Al(ClO₄)₃

Serum ion and standard ion solutions were analyzed according to the following procedure: To 1.00ml of unknown & std samples are added 2.00ml of reducing agent and 2.00ml of acid to reduce and release Fe from transferrin. The serum proteins are then precipitated with 1.00ml of 30% by weight trichloroactic acid. The mixture is then centrifuged to remove the protein. A 4.00ml aliquot of each solution is then transferred to a fresh test-tube and treated with 1.00ml of a solution containing ferrozine and buffer. The absorbance of this solution was then measured after a 10-minute period to develop the color. The following data were obtained:

Blank=0.018 Abs at 562nm in a 1.00cm cell

Std, 1.00ml of 3ug/ml Fe standard solution, treated as the above procedure=0.209 Abs

Unknown serum sample, 1.00ml treated as above=0.169 Abs

Find the concentration of Fe in the sample, in ppm and M. Also, if the complex that is formed is the complex FeL3, calculate the epsilon value for the complex.

Propose a structure for the compound that has the following spectra: NMR: δ 1.28 (3H, t, J = 7 Hz); δ 3.91 (2H, q, J = 7 Hz); δ 5.0 (1H, d, J = 4 Hz); δ 6.49 (1H, d, J = 4 Hz) ppm IR: 3100, 1644 (strong), 1104, 1166, 694 cm -1 (strong) no IR absorptions in the range 700-1100 cm -1 or above 3100 cm-1 Mass spectrum: m/z = 152, 150 (equal intensity; double molecular ion)

Air is separated into two product streams in a separator operating at steady state. One product stream is 98 mol% oxygen, and it contains 80% of the oxygen in the air fed to the column. The other product stream is mostly nitrogen. To a good approximation, air is 79 mol% nitrogen and 21 mol% oxygen.

Calculate the quantity of air required, in tons/day, to produce 1 ton/day of the oxygen product. In addition, calculate the mol% nitrogen in the second product stream.

On the basis of LeChâtelier’s Principle, explain why Ag2CO3 dissolves when HNO3 is added.

In atomic absorption spectrometry, why is "modulation" of the line source necessary for accurate results and how is modulation achieved?

Ethyl acetate, a solvent used in many fingernail-polish removers, is made by the reaction of acetic acid with ethanol: CH3CO2H(soln)Aceticacid +C2H5OH(soln)Ethanol⇌CH3CO2H(soln)Ethylacetate+H2O(soln)ΔH∘=−2.9kJ

Part A

Does the amount of ethyl acetate in an equilibrium mixture increase or decrease when the temperature is increased? Does the amount of ethyl acetate in an equilibrium mixture increase or decrease when the temperature is increased?

increase

decrease

Part B

How does Kc change when the temperature is decreased? Justify your answers using Le Chatelier's principle.

1- As the temperature is decreased, the reaction shifts from left to right. The product concentrations increase, and the reactant concentrations decrease. This corresponds to an increase in Kc.

2- As the temperature is decreased, the reaction shifts from right to left. The product concentrations decrease, and the reactant concentrations increase. This corresponds to an decrease in Kc.

3-As there is neither products no reactants in gas state the temperature does not shift the reaction. So decrease in temperature does not change Kc. SubmitMy AnswersGive Up

 

Assume a biological process can be performed in either a plug flow or completely mixed flow reactor, and the process has a first-order reaction rate K of 0.5 hr^-1. Assume an influent concentration of 100 mg/L, a regulatory required effluent concentration of 10 mg/L, and a flow rate of 100 m³/hr.

a.   What reactor volume (m³) is required if one completely mixed reactor is used?

HINT: use the equation for a first order reaction with a CMR.

b.   What reactor volume (m³) is required if one plug flow reactor is used?

The equation for CMRs-in-series with a first-order reaction is , where V is the total volume of all reactors in the series, Q is the flow rate, “n” the number of reactors, C_o is the influent concentration to the series of reactors, and C_n is the concentration after “n” reactors. The residence time (Q) of each of reactors-in-series is V/(n Q). Thus, the total residence time is: Q_total = n Q, if Q is the residence time of each reactor tank. Be careful about the volume of each reactor

c.   What is the required TOTAL volume (m³) for four completely mixed reactors in series? Note in the above equation, this total volume is “V” in the above equation.

d.   Which of a, b, and c results in the smallest reactor volume? What are the ratios of the other two total reactor volumes to the “smallest” reactor volume?

e. All other things equal (other than reactor volume and thus cost), in selection of the type of reactor what is the order of preference (for these three reactor options) that you would if you were a consulting engineer?

DIPF and Sarin and "organophosphate" insecticides are all irreversible inhibitors of enzymes with a "special" -- highly reactive -- active-site Ser residue. Which of the following is true about DIPF (or Sarin or organophosphate insecticides)?

A.)	DIPF forms a covalent phosphoester bond to the side chain of a Ser residue in enzymes that DIPF inhibits.

B.) DIPF (or Sarin or organophosphate insecticides) cannot kill humans (or any vertebrate).

C.) DIPF inhibition is reversible. Hence, an EI complex is analogous to an ES complex.

D.)After DIPF reacts with an enzyme (to inhibit it) the phosphate part of DIPF is released and the rest of the molecule, including F, remains attached to the enzyme.

E.) none of the above is a true statement.

Calculate the vapor pressure of water above a solution prepared by dissolving 27.0 g of glycerin (C3H8O3) in 135 g of water at 343 K. (The vapor pressure of water at 343 K is 233.7 torr.)

Ph2o=?

Calculate the mass of ethylene glycol (C2H6O2) that must be added to 1.00 kg of ethanol (C2H5OH) to reduce its vapor pressure by 9.00 torr at 35∘C. The vapor pressure of pure ethanol at 35∘C is 1.00×102 torr.

m=?

Given Kc = 1.5 × 10¹⁸ at 300 K for the reaction below

2 NO----->   N₂ +   O₂

900 mg of NO were initially placed in a 1.00 L vessel and the reaction was allowed to reach equilibrium.Calculate the equilibrium concentrations of NO, N₂, and O₂.

C₂H₂ (g) + 3H₂ (g) --> 2CH₄ (g)

ΔH_f:    227                                  -75      (kJ/mol)

S°:    201            131               186      (J/mol K)

For the above reaction, what is ΔS, in J/mol K?