The Cherry Kool Aid dispensed from the burette was prepared as per the package instructions. The suggested serving size of Kool Aid is 8.0 ounces. How many moles and grams of red 40 (MW=496.42g/mol) are found in a serving fo Cherry Kool Aid? ( HInt: Use the concentration of undiluted Kool Aid you determined in the lab= 0.092mM )
In: Chemistry
Calculate [OH?] and pH for strong base solution formed by mixing 15.0mL of 1.00
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What volume, in milliliters, of 0.160 M0.160 M NaOH NaOH should be added to a 0.140 L0.140 L solution of 0.021 M0.021 M glycine hydrochloride (pKa1=2.350,Ka1=2.350, pKa2Ka2 = 9.7789.778) to adjust the pH to 2.61?
In: Chemistry
The pkb values for the dibasic base B are pkb1 = 2.10 and pkb2 = 7.34. Calculate the pH at each of the following points in the titration of 50.0 mL of a 0.50 M B(aq) with 0.50 M HCl (aq).
a) before addition of any HCl d) after addition of 75.0 mL of HCl
b) after addition of 25.0 mL of HCl e) after addition of 100.0 mL of HCl
c) after addition of 50.0 mL of HCl
In: Chemistry
Deducing a Reaction Mechanism for the Isomerization of Maleic acid to fumaric acid. I'm completing my organic chemistry lab report and answering questions and I have very confused and would appreciate any help and explanation please. I appreciate it.
|
Test Tube |
Solids |
Solvents |
Precipitate |
|
A |
1.0 g maleic acid |
3.0 mL 6 M HCl |
Yes |
|
B |
1.0 g maleic acid |
3.0 mL 3 M H2SO4 |
No |
|
C |
1.0 g maleic acid 0.5 g ammonium chloride |
3.0 mL distilled water |
No |
|
D |
1.0 g maleic acid 0.5 g ammonium chloride |
3.0 mL 6 M HCl |
Yes |
|
E |
1.0 g malic acid |
3.0 mL 6 M HCl |
No |
|
F |
1.0 g maleic acid |
1.5 mL distilled water 2.0 mL conc. HBr |
Yes |
Possible Mechanisms for the Isomerization.
1. Maleic acid is activiated by visible light, and then rearranges to form fumaric acid. In this mechanism, the pi-bond is momentarily broken, allowing for the free rotation to give the more stable trans isomer. The double bond then reforms.
2. The rearrangement of maleic acid to fumaric acid is accomplished by the thermal excitation of the molecule. In this mechanism, the pi-bond is broken by the application of heat. As described above, this would allow rotation to occur and form the more stable trans isomer.
3. A nudeophilic addition of a chloride ion to maleic acid again permits free rotation, followed by release of the Cl- ion to produce fumaric acid.
4. An electrophilic addition of a proton to maleic acid, followed by rotation and then deprotonation.
5. Water adds to maleic acid (under acid catalysis) to form laic acid. Malic acid then rotates to a new conformation and elimenates water to form fumaric acid.
6. The addition of a proton to maleic acid leads to the formation of a lactone (cyclic ester) which undergoes a ring opening reaction to yield malic acid. Malic acid is then dehydrated to give fumaric acid.
7. A proton adds to the carbonyl oxygen to give an intermediate with a number of resonance structures. One of these resonance structures can freely rotate and deprotonation to give fumaric acid.
8. A proton adds to the carbonyl oxygen, followed by an addtion of a chloride ion. The product of this 1,4 addition then undergoes a free rotation, and hydrochloric acid is eliminated to produce fumaric acid.
So, I understand that I can go through a process and eliminate the first 7 reaction mechanisms to chose the last one #8 is close to the true state of affairs.
But I am struggling answering these questions, if anyone can help and provide an explanation I'd greatly appreciate it.
Questions #1: 1. Is visible light solely responsible for the isomerization of maleic acid to fumaric acid? Explain.
2. If the isomerization of maleic acid to fumaric acid is a thermal effect, which test tubes should contain fumaric acid?
3. For mechanism 3 to be correct, which test tubes should contain fumaric acid?
4. For mechanism 4 to be correct, which test tubes should contain fumaric acid?
5. For mechanism 5 to be correct, which test tubes must contain fumaric acid?
6. Which test might rule out mechanism 6 as a possibility?
7. For mechanism 7 to be correct, which test tubes must contain fumaric acid?
8. For mechanism 8 to be correct, which test tubes must contain fumaric acid?
Then these questions:
1. Does sulfuric acid, which ionizes to give a negatively charged sulfate ion, induce the isomerization of maleic acid to fumaric acid? Explain.
Anybody answer this?
In: Chemistry
What are some explanations for a yield going above 100%? Referring specifically to a yield produced when re-using products from a previous experiment (re-using recovered NaI to produce CuI).
In: Chemistry
how many moles are in 6ml of 85% H3PO4? and how many grams of sodium carbonate are needed to neutralize this acid?
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9. Discuss the trend in electronegativities across Period 2 from lithium to fluorine. Can you account for the difference in details from the trend in ionization energy?
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Hartree-Fock self-consistent field theory can deliver the best possible wavefunction for a multielectron atom.
The Hartee-Fock energy is always lower than the real energy by an amount that is referred to as the correlation energy.
According to Variation Theory, it is possible to compute a He energy of -86.7 eV.
Zeff is a parameter in the exact wavefunction of He.
The following wavefunction would be acceptable for a 2-electron system: [f(1)g(2)][α(1)β(2)-α(2)β(1)].
The Born-Oppenheimer approximation permits the separation of the electronic and nuclear components of
the wavefunction.
N2- is paramagnetic.
In HMO theory, the overlap integral assumption is accurate
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The following reaction was carried out in a 3.75Lreaction vessel at 1100 K:
C(s)+H2O(g)?CO(g)+H2(g)
If during the course of the reaction, the vessel is found to contain 8.25mol of C, 13.3mol of H2O, 3.40mol of CO, and 6.00mol of H2, what is the reaction quotient Q?
In: Chemistry
For the exothermic reaction
PCl3(g)+Cl2(g)?PCl5(g)
Kp = 0.100 at a certain temperature. A flask is charged with 0.500 atm PCl3 , 0.500 atm Cl2, and 0.300atm PCl5 at this temperature.
What are the equilibrium partial pressures of PCl3 , Cl2, and PCl5, respectively?
Express your answers numerically in atmospheres with three digits after the decimal point, separated by commas.
In: Chemistry
Electron transfer translocates protons from the mitochondrial matrix to the external medium, establishing a pH gradient across the inner membrane (outside more acidic than inside). The tendency of protons to diffuse back into the matrix is the driving force for ATP synthesis by ATP synthase. During oxidative phosphorylation by a suspension of mitochondria in a medium of pH 7.4, the pH of the matrix has been measured as 7.7.
(a) Calculate [H+ ] in the external medium and in the matrix under these conditions.
(b) What is the outside-to-inside ratio of [H+ ]? Comment on the energy inherent in this concentration difference (just the energy from the concentration gradient, not the electrochemical potential.
(c) Calculate the number of protons in a respiring liver mitochondrion, assuming its inner matrix compartment is a sphere of diameter 1.5 microns. (volume of a sphere is 4/3 π r^3)
(d) From these data, is the concentration gradient sufficient to generate ATP from ADP and Pi? If not, suggest how the necessary energy for synthesis of ATP from ADP and phosphate arises.
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What is the pH of a 203 mL sample of 3.601 M acetic acid (CH3COOH) (Ka = 1.8 x 10-5)?
In: Chemistry
1. Using the standard enthalpies of formation, what is the standard enthalpy of reaction?
CO(g) + H2O(g) --> CO2(g) + H2(g)
2. Calculate the standard enthalpy change for the following reaction at 25 �C.
HCl(g) + NaOH(s) --> NaCl(s) + H2O(l)
3. For a particular isomer of C8H18, the following reaction produces 5113.3 kJ of heat per mole of C8H18(g) consumed, under standard conditions.
C8H18(g) + 25/2O2(g) --> 8CO2(g) + 9H2O(g) (deltarxn = -5113.3 kJ)
What is the standard enthalpy of formation of this isomer of C8H18(g)?
4. Many power plants produce energy by burning carbon-based fuels, which also produces carbon dioxide. Carbon dioxide is a greenhouse gas, so over-production can have negative effects on the environment. Use enthalpy of formation data to calculate the number of moles of CO2(g) produced per megajoule of heat released from the combustion of each fuel under standard conditions (1 atm and 25 �C).
coal, C(s, graphite):
natural gas, CH4(g):
propane, C3H8(g):
octane, C8H18(l) (?Hf� = �250.1 kJ �mol-1):
In: Chemistry