Compare and contrast the BCA and Bradford methods for protein concentration determination. How does each work? Give an example of something that interferes with these methods and explain where each works better than the other. Be as specific as possible.
In: Chemistry
You want to maintain pH = 7.0 for an enzyme-catalyzed reaction that will produce hydrogen ions along with the desired product. At equal concentrations, which weak acid, if any, will serve as the better buffer for the reaction: Acid A pKa = 6.5, Acid B pKa = 7.5
a. Acid A
b. both are equally effective
c. water is as good as either of the acids available
d. acid B
*** I get that answer A is correct but Wouldn't B (pKa = 7.5) be better because as more H+ gets released by the reaction the pH would go down closer to 7, while if A was used the pH would fall further away from 7 . Also I'm not sure what is at "equal concentrations" as in the question
In: Chemistry
A shelf containing several chemicals, Salicylic acid, 4-(4-Hydroxyphenyl)butan-2-one (a.k.a. Raspberry Ketone) and 4-methylaniline, fell and the vials shattered. The white powders are hopelessly mixed in a dustpan. You are promised a raise if you can devise a procedure that a less qualified chemist will follow to separate the three compounds. You must describe what extraction steps are to be taken at each point of the separation and how to isolate and purify each compound again as a solid. To ensure that you get the raise, you will also need to suggest how to determine the purity of each recovered sample.
In: Chemistry
The specific rotation of optically pure (2S,3S)-tartaric acid is -12°. The optical rotation of an impure sample containing a mixture of enantiomers of this compound was measured to be -9°. In the boxes below, write the percentages of the specified stereoisomers present in the sample. Show your work below.
Percentage of (2S,3S)-tartaric acid?
Percentage of (2R,3R)-tartaric acid?
What is the specific rotation of pure (2S,3R)-tartaric acid? How do you know?
In: Chemistry
Calculate [H30] for the following solutions. a) 6.16 x 10 ^-3 M HBr b) 1.80 x 10^-2 M KOH
In: Chemistry
I need to come up with a a separation and purification scheme procedure for 50% benzoic acid, 40% benzoin, and 1,4-dibromobenzene having the following reagents available: 1M NaOH, 6M NaOH, 1M HCl, 6M HCl, 1M NaHCO3, saturated sodium chloride, diethyl ether, 95% ethanol, methanol, isopropyl alcohol, acetone, hexane, toluene, methylene chloride, and granular anhydrous sulfate
In: Chemistry
a) Show the full balanced equation of Benzaldehyde + Sodium Cyanide -> Benzoin. Stoichiometry ratio should be 2:1. Ratio of -CN to benzoic is 1:1 if that even helps. Rely on Sodium Cyanide being 0.54M in 95% Ethanol. b) Use the density of benzaldehyde to calculate its mass. 400 microliters were used in my experiment, and the MW is 106.13. C) Thus, Find the Limiting Reagent, Theoretical yield, and % Yield of Benzoin. Obtained yield in experiment was .0246g benzoin crystals, and again, 400microliters of benzaldehyde used AND 4mL of Sodium Cyanide (0.54M in95% ethanol) was used. PLEASE SHOW NICE LEGIBLE WORK SO I CAN UNDERSTAND WHAT IS GOING ON.
In: Chemistry
Please calculate the adiabatic flame temperature for methanol combustion for the following case : 12% CH3OH (g) in air at 1 atm when the maximum possible conversion of methanol is achieved. It is believed that CO is not formed during the combustion.
In: Chemistry
Acetone and Ethanol have similar molar masses but significantly different delta T values. Explain this based on their intermolecular forces. The delta T values calculated were -13 for Ethanol and -22 for Acetone.
In: Chemistry
For each reaction listed, determine its standard cell potential
(in V) at 25°C and whether the reaction is spontaneous at standard
conditions.
(a)
Co2+(aq) + Mg(s) → Co(s) + Mg2+(aq)
ΔE° = V
(b)
2 Al(s) + 3 Cu2+(aq) → 2 Al3+(aq) + 3 Cu(s)
ΔE° = V
(c)
Ag(s) + Cu(NO3)2(aq) → AgNO3(aq) + CuNO3(aq)
ΔE° =
(d)
Ni(s) + Zn(NO3)2(aq) → Ni(NO3)2(aq) + Zn(s)
ΔE° =
In: Chemistry
For triatomic molecules (i.e., molecules that contain three atoms) such as difluorine monoxide, F2O, there are only two possible molecular geometries, linear or bent.
a. Draw the Lewis structure for F2O (O is the central atom), and predict the molecular geometry using the VSEPR model.
b. Could infrared spectroscopy be used to confirm the molecular geometry that is predicted using the VSEPR model? That is, could the infrared spectrum for F2O be used to determine whether the molecule is linear or bent? Explain your reasoning.
In: Chemistry
Explain how the determination of the rate law equation significantly differs from the determination of the equilibrium constant Keq expression.
In: Chemistry
1. A solution of AgNO3 contains 30 g/liter. What volume of this
solution is needed to
react with 0.60 g of 65% pure AlCl3?
In: Chemistry
What fraction of 1,6-hexanedoic acid (adipic acid) is in each form (H2A, HA−, A2−) at pH 5.00?
In: Chemistry
calculate Ecell for each of the following cells.
Al(s)|Al3+( 0.20M )||Fe2+( 0.90M )|Fe(s)
Ag(s)|Ag+( 0.38M )||Cl-( 0.094M )|Cl2(g, 0.60atm )|Pt(s)
In: Chemistry