The space shuttle carries about 7.35×10⁴ kg of solid aluminum fuel, which is oxidized with ammonium perchlorate according to the following reaction:
10Al(s)+6NH4ClO4(s)→4Al2O3(s)+2AlCl3(s)+12H2O(g)+3N2(g)
The space shuttle also carries about 6.02×10⁵ kg of oxygen (which reacts with hydrogen to form gaseous water).

Part A

Assuming that aluminum and oxygen are the limiting reactants, determine the total energy produced by these fuels. (ΔH∘ffor solid ammonium perchlorate is -295 kJ/mol.)

Part B

Suppose that a future space shuttle was powered by matter-antimatter annihilation. The matter could be normal hydrogen (containing a proton and an electron) and the antimatter could be antihydrogen (containing an antiproton and a positron). What mass of antimatter would be required to produce the energy equivalent of the aluminum and oxygen fuel currently carried on the space shuttle?

Part A

Pick an appropriate solvent to dissolve isopropyl alcohol (polar, contains an OHOH group) .

Check all that apply.

Part B

State the kind of intermolecular forces that would occur between the solute and solvent in isopropyl alcohol (polar, contains an OHOH group) .

Check all that apply.

Part C

Pick appropriate solvent(s) to dissolve sodium chloride (ionic).

Check all that apply.

Part D

State the kind of intermolecular forces that would occur between the solute and solvent in sodium chloride (ionic).

Check all that apply.

Part E

Pick appropriate solvent(s) to dissolve paraffine oil (nonpolar).

Check all that apply.

Part F

State the kind of intermolecular forces that would occur between the solute and solvent in paraffine oil (nonpolar).

Check all that apply.

SubmitRequest Answer

Part G

Pick an appropriate solvent to dissolve sodium nitrate (ionic).

Check all that apply.

Part H

State the kind of intermolecular forces that would occur between the solute and solvent in sodium nitrate (ionic).

Check all that apply.

Calculate the work (in kJ) when 2.60 moles of methane react with excess oxygen at 363 K:

CH₄(g) + 2O₂(g) ? CO₂(g) + 2H₂O(l)

Explain how FTIR-ATR is capable of measuring the absorbance of IR radiation without projecting the radiation directly through a sample container to a detector on the other side.

In the body, hemoglobin (Hb) is the substance responsible for transporting oxygen (O2) to tissues. Hemoglobin binds oxygen to produce oxyhemoglobin (HbO2):

Hb + O2 ? HbO2

Carbon monoxide (CO) can also bind to hemoglobin to produce carboxyhemoglobin (HbCO):

Hb + CO ? HbCO

The equilibrium constant for Reaction 2 (KCO) is about 210 times larger than the equilibrium constant for Reaction 1 (KO2). Thus, carbon monoxide binds to hemoglobin much more efficiently than oxygen.

KCO/KO2 = 210

a. Write a balanced equation for the displacement of oxygen from HbO2 by CO to produce HbCO. Write the equilibrium constant expression for your overall reaction.

b. Write an expression that relates the equilibrium constant for the overall reaction (i.e., from Question 1) to the equilibrium constants KCO and KO2.

c. Use your balanced equation from part (a) and your knowledge of equilibrium constants to explain why patients who are experiencing CO poisoning are generally given pure oxygen as a remedy.

What is the age of the charcoal BP if currently living organisms decay at the rate of 15.3 disintegrations/min per gram of carbon?

The half-life of 14C is 5715 years.

A sample of pure NO2 is heated to 336?C at which temperature it partially dissociates according to the equation
2NO2(g)?2NO(g)+O2(g)
At equilibrium the density of the gas mixture is 0.525g/L at 0.755atm . Calculate Kc for the reaction. Thank you for your help!

Use the method of successive approximations to determine the pH and concentrations of H2A, HA–, and A2– in a solution of 0.00250 M monopotassium fumarate (KHA). The pKa values for fumaric acid are 3.02 (pKa1) and 4.48 (pKa2). PH= ? [H2A]= ? [HA-] = ? [A2-]= ?

1. A CSTR and a PFR of equal volume (VCSTR = VPFR = V) are used to degrade a compound in a first-order manner under steady-state conditions.

(a) If the CSTR gives a 80% degradation what is the efficiency of the PFR?

(b) If instead of one CSTR of volume V, you use 5 CSTRs in series, each having a volume of 0.2V, what would be the overall degradation efficiency?

(c) Show that the overall efficiency will be equal to that of the PFR (volume V) if you use an infinite number (n→∞) of CSTRs in series each having a volume of V/n.

Ammonia is a weak base with a Kb of 1.8×10^-5. A 140.0-mL sample of a 0.175 M solution of aqueous ammonia is titrated with a 0.106 M solution of the strong acid HCI. The reaction is

NH3(aq)+HCl(aq)→NH+4(aq)+Ci−(aq)NH3(aq)+HCl(aq)→NH+4(aq)+Ci−(aq)

Compute the pH of the titration solution before any acid is added, when the titration is at the half-equi valence point, when the titration is at the equivalence point, and when the titration is 1.00 mL past the equivalence point

The recommended adult dose of Elixophyllin, a drug used to treat asthma, is 6.00 mg/kg of body mass. Calculate the dose in milligrams for a 134-lb person.

Calibration of a glass electrode gave a reading of 139.7 mV with saturated potassium hydrogen tartrate buffer standard (pH = 3.557) and a reading of -92.2 mV with 0.08 m HEPES, 0.08 m NaHEPES, 0.08 m NaCl buffer standard (pH = 7.454), both measured at 30°C.

(a) What is the observed slope (mV/pH unit) of the calibration curve?

(b) What is the theoretical slope at 30°C?

(c) What is β, the electromotive efficiency to three significant figures?? Open the hint panel below for the definition of electromotive efficiency.

(d) What is the pH of an unknown that gives a reading of 46.9 mV with this electrode at 30°C?

Write the balanced equation for the combustion of aqueous citric acid. Determine the standard molar enthalpy of aqueous citric acid. citric acid can constitute 8% of the dry weight of limes if a typical lime contains 30 ml of juice how much energy is released when one lime is combusted?

A compound of molecular formula C7H13Br is a tertiary bromide, is optically inactive, and has one primary carbon atom. C7H13Br is inert to catalytic hydrogenation. C7H13Br is reacted with another unknown compound. Thin-layer chromatography of the product mixture shows that two products are formed. GC analysis shows that the two products are formed in unequal amounts. Upon isolation from each other via distillation, both isolated products are optically inactive. Both products de-colorize molecular bromine.

Answer questions a-c below.

a. Based on the information provided, is the reaction between the tertiary bromide and the unknown compound a: 1. substitution, or 2. elimination reaction? ________

b. Will the organic starting material give a positive (P) or negative (N) result for the silver nitrate in alcohol test? ________

c. Propose a structure for C7H13Br. Name the structure.

1. Write the balanced equation (not the mechanism) for the protonation of nitric acid by sulfuric acid, represented as an equilibrium expression.

2. Write the equilibrium constant expression for the reaction shown in question 1 above.

3. Consider the pKa values shown below:

H2SO4: -3

HSO4!: +2

HNO3: -1.3

H2NO3+: -13

Based on these pKa values, determine the equilibrium constant for the reaction that you wrote down for question 1.

4. The proton NMR spectrum of chlorobenzene was examined by Hiyamizu and coworkers in 1968. Their analysis revealed the following chemical shifts. The hydrogens ortho to the chlorine are at 7.28 ppm. The hydrogens meta to the chlorine are at 7.23 ppm. The hydrogen para to the chlorine is at 7.16 ppm.

A) Use arrow formalisms to draw resonance structures of chlorobenzene using the chlorine as an electron donor.

B) One might expect that the positions that have negative charges (and hence excess electron density) in the resonance structures would be the most upfield, but this is not the case. Explain why, and explain why the chemical shifts appear where they do relative to each other.