What is the ph of the endpoint of the titration of a 25.00mL sample of .10M HAc (60.05g/mol) using .10M NaOH as the titrant? Ka for HAc is 1.75x10^-5
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The enzyme urease catalyzes the reaction of urea, (NH2CONH2), with water to produce carbon dioxide and ammonia. In water, without the enzyme, the reaction proceeds with a first-order rate constant of 4.15 ×10−5s−1 at 100 ∘C. In the presence of the enzyme in water, the reaction proceeds with a rate constant of 3.4 ×104s−1 at 21 ∘C
1.If the rate of the catalyzed reaction were the same at 100 ∘C as it is at 21 ∘C, what would be the difference in the activation energy between the catalyzed and uncatalyzed reactions? Express your answer using two significant figures.
2.
In actuality, what would you expect for the rate of the catalyzed reaction at 100 ∘C as compared to that at 21 ∘C?
In actuality, what would you expect for the rate of the catalyzed reaction at 100 as compared to that at 21 ?
| The rate of the catalyzed reaction will be significantly lower at 100 ∘C than at 21 ∘C. | |
| The rate of the catalyzed reaction will be significantly greater at 100 ∘C than at 21 ∘C. | |
| The rate of the catalyzed reaction will be at 100 ∘C will be nearly equal to the rate at 21 ∘C. |
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Chromatography
a)Provide a detailed explanation for the phenomenon of electro-osmotic flow?
b)What is the name of the separation technique this phenomenon is associated with?
c)What is the result of eletro-osmotic flow for your analysis?
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1.Determine the number of moles of ATP that can be synthesized from one mole of CH3(CH2)22COOH. (Show all your work.)
2.Why does the oxidation of unsaturated fatty acids such as oleic acid require additional enzymes? How does the presence of a carbon-carbon double bond change the total number of ATP that can be produced?
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Calculate the pH at 25 degrees Celcius of a 0.35M aqueous solution of phosphoric acid (H3PO4). (Ka1, Ka2, and Ka3 for phosphoric acid are 7.5x10^-3, 6.25x10^-8, and 4.8x10^-13, respectively.)
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A reaction
A (aq) + B (aq) <--> C (aq)
has a standard free-energy change of –3.85 kJ/mol at 25 °C. What are the concentrations of A, B, and C at equilibrium if, at the beginning of the reaction, their concentrations are 0.30 M, 0.40 M, and 0 M, respectively?
[A]= M
[B]= M
[C]= M
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The intermediate product of a chemical process is a chemical paste that is saturated with water. The paste is rolled into a thin layer and placed to dry in a flat area 30m long 15m wide. Drying is enhanced by blowing hot air over the paste, and the mass transfer coefficient is 0.017 m/s. Diffusion of water through the paste is rapid so that the concentration of water vapor at the surface of the paste remains constant at 0.002 gmol/L. Water must be removed from the paste remains at a minimum rate of 9.5 L/min (liquid volume). (Note:MW water=18 and p water=1 g/cm^3.) a.) What mechanism controls the transfer of water from the paste in the air? b.) What is the molar rate of water removal that corresponds to a volumetric removal rate of 9.5 L/min? C.) What is the maximum concentration of water vapor allowable in the air (far from the paste surface) if water must be removed at a rate of at least 9.5 L/min? D.) Assuming that the mass transfer coefficient remains constant, what can be done to increase the rate of water removal from the paste?
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How much 5.50 M NaOH must be added to 500mL of a buffer that is .0180 M Acetic Acid and .0250 M sodium acetate to raise the pH of 5.75?
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(a) The cell of interest in this figure is: Cu(s) | CuSO4(aq, 1.0 M) | KCl(aq, 3 M) | AgCl(s) | Ag(s) Write reduction half-reactions for this cell. (Omit states-of-matter from your answer.)
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A sample of a copper ore with a mass of 0.4225 g was dissolved in acid. A solution of potassium iodide was added, which caused the reaction:
2Cu2+(aq) + 5I
In: Chemistry
When SbCl3(g) (0.001539 mol/L) and 0.6772 mol of Cl2(g) in a 440.0 L reaction vessel at 665.0 K are allowed to come to equilibrium the mixture contains 0.0009506 mol/L of SbCl5(g). What is the concentration (mol/L) of SbCl3(g)? SbCl3(g)+Cl2(g) = SbCl5(g)
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Why was your measured refractive index different from the value given in the lab report?
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A proton is located at a distance of 0.049 m from a point charge of +8.30 ?C. The repulsive electric force moves the proton until it is at a distance of 0.16 m from the charge. Suppose that the electric potential energy lost by the system were carried off by a photon. What would be its wavelength?
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1. What is the reason why activites are often called effective concentrations? Explain why there are differences between activities and concentrations.
2. Methane dissociates into H2(g) and C(s, graphite).
- Calculate the equilibrium constant K at 298 K.
- Calculate K at 50°C (assuming that ΔrH^Θ is temperature independent.
- Calculate α (degree of dissociation of methane) at 25°C and a total pressure of 0.010 bar.
3. What is the value of ΔrG for the reaction
NO2(g) ⇔ N2O4(g) when
Q = 0.1
Q = 1.0
Q = 10.0
Q= 100.0
Estimate (by interpolation) the value of K from the values you calculated.
Compare with the value obtained from the thermodynamic definition of the equilibrium constant.
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Consider separate 1.0 L samples of the following gases at STP: Cl2, C2H6, and Xe. Which of the following statements are true regarding these gas samples?
The C2H6 gas sample has the smallest average kinetic energy.
The mass of the gas in each container is the same.
The C2H6 gas molecules collide with the container walls most frequently.
The C2H6 gas sample has the lowest density.
Each Cl2 gas particle collision with the container wall is more forceful as compared to each C2H6 and Xe collision.
The Cl2 gas sample has the most molecules of gas present.
In: Chemistry