An aluminum rod is subject to electrolysis in an aqueous solution resulting in the production of Al2O3

at the _______________ and H2 gas at the _______________.

a. Give the balanced anode and cathode half reactions.

Anode Half-Reaction:______________________________________________________________________________________

Cathode Half-Reaction:____________________________________________________________________________________

b. How many grams of Al2O3 are produced using a constant current of 142 A for 5.00 minutes?

Answer:____________________________

c. How many minutes are required to produce 2.00 L of H2 gas at STP at a constant current of 142 A?

Answer:____________________________

Part A

How long does it take a person at rest to breathe one mole of air if the person breathes 84.0 mL/s of air that is measured at 25 ∘C and 755 mmHg? Express your answer numerically in seconds.

Part B

Typically, when a person coughs, he or she first inhales about 2.50 L of air at 1.00 atm and 25 ∘C. The epiglottis and the vocal cords then shut, trapping the air in the lungs, where it is warmed to 37 ∘C and compressed to a volume of about 1.70L by the action of the diaphragm and chest muscles. The sudden opening of the epiglottis and vocal cords releases this air explosively. Just prior to this release, what is the approximate pressure of the gas inside the lungs?

Express your answer numerically in atmospheres.

Part C

Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles) of He is present in a helium-oxygen mixture having a density of 0.508 g/L at 25 ∘C and 721 mmHg?

Express your answer numerically as a percentage.

-Please Check my calculations-

Mass Data for preparation of Alum

Mass Weighing paper: 0.3832 grams

Mass Weighing paper plus Aluminum: 1.3838 grams

Mass of watch glass: 56.5001 grams

Mass of watch glass plus dry alum: 68.8550

Balanced Equation: 2Al(s)+2KOH(aq)+4H2SO4(aq)+22H2O(l)=2KAl(SO4)2*12H2O(s)+3H2(g)

Yields of Alum

Mass of aluminum: 1.0006 grams

Mass of dry alum: 12.354 grams

Theoretical Yield:

1.0006/26.98 = .03709 moles Al (Mass Aluminum/Molar Mass)

.03709 * 474.3884g/mole Alum = 17.595 grams Alum (Moles Al/Molar Mass of Alum)

Percent Yield

Actual/Theoritical x 100%

12.3549/17.595 = .7022 *100= 70.22%

A.) what is the normality of Na2C2O4 solution if you use 1.14g of Na2C2O4 to prepare 100.00 mL of solution?

B.) what is the normality of the stock KMnO4 solution if it took 31.20 mL of the KMnO4 solution to titrate a 20.00 mL sample of the oxalate solution prepared in part a?

The pKa of the α-carboxyl group of phenylalanine is 1.83, and the pKa of its α-amino group is 9.13. Calculate the average net charge on phenylalanine if it is in a solution that has a pH of 8.20. If the charge is positive, do not enter a + sign.

Determine the Kanfor a .035 M weak (monoprotic) acid with a ph of 3.5. Show work too please?

how to make a mole fraction of 0.25, 0.50, 0.75 ethyl acetate and cyclohexane having a total volume of 5 or 10 ml

Be sure to answer all parts.

Find the pH during the titration of 20.00 mL of 0.1000 M triethylamine, (CH₃CH₂)₃N

(

K_b = 5.2

×

10⁻⁴

)

,

with 0.1000 M HCl solution after the following additions of titrant.

(a) 10.00 mL:

pH =

(b) 20.50 mL:

pH =

(c) 25.00 mL:

pH =

What is the concentration of a NH₃ solution having a pH of 11.15?

Methanol and ethanol are both oxidized by alcohol dehydrogenase (ADH). Methanol is poisonous because it is oxidized by ADH to form the highly toxic compound formaldehyde. The adult body has 40 L of water, throughout which these alcohols are rapidly and uniformly distributed. The densities of both alcohols are 0.79 g/mL. The Km of ADH for ethanol is 1.0x10-­‐3 M, and for methanol the Km is 1.0x10-­‐2 M. The molecular mass of methanol is 32 g/mol and that of ethanol is 46 g/mol. If an individual consumed 100 mL of methanol (a leathal amount), how much 100-­‐proof whiskey (50% ethanol by volume) must this person consume in order to reduce the activity of ADH toward methanol to 5%? Assume the Ki for ethanol = Km.

Given:

Ka1= 7.5*10^-3

Ka2=6.2*10^-8

Ka3=4.2*10^-13

What is the pH of a solution of 0.550 M K2HPO4, potassium hydrogen phosphate?

What is the pH of a solution of 0.400 M KH2PO4, potassium dihydrogen phosphate?

calculate the formula mass of each compound given below. keep at least one decimal place in atomic masses from the periodic table. a) hydrogen peroxide, H2O2. b) sulfuric acid, H2SO4.

Calculate the change in entropy when 108 ml of hot (97 oC) water added to 36 ml cold (5 oC) water in a closed Styrofoam cup given that C_p (H₂O, l) = 75.5 J/(mol * K)

200. g of liquid phase octane (C8H18) are burned in air at a temperature of 100. degrees Celsius and a pressure of 1.00 atm, forming vapor phase water and carbon dioxide.

a) Write the balanced chemical reaction equation for this process.

b) What is the magnitude of the difference between ΔE and ΔH for one mole of octane going through this process? (Hint: use the value of R that makes life easiest.)

c) The reaction is in contact with a reservoir of water that is also at 100 degrees Celsius. If that reservoir absorbs all of the heat released by the reaction (of the 200. g of octane), how many moles of the water will evaporate? Each mole of C8H18 releases 5074.482 kJ of heat when it goes through this process.

Part a I got no problem, but I can't seem to figure out parts b and c. Thanks for the help!!

.