I made a solution of fluorscein and diluted it with ethanol, and I was confused about some stuff.
Does emission and excitation depend on concentration?
Would would change if I diluted it with water rather than ethanol?
What is stoke's shift and what is an anti - stoke?
In: Chemistry
The following compounds can be formed during the Maillard reaction. For each compound:
|
Compound |
From Caramelization? (Y/N) |
Color |
Aroma/Taste |
#O’s |
#N’s |
#S’s |
Ring Y/N |
C=O Y/N |
|
Diacetyl |
||||||||
|
2,4,5-trimethyl thiazole |
||||||||
|
2-acetyl-3,5-dimethyl pyrazine |
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|
Difurfuryl sulfide |
||||||||
|
3-ethyl pyridine |
||||||||
|
Furfural |
||||||||
|
Levulinic acid |
||||||||
|
1-methyl pyrrole |
||||||||
|
Phenylpyruvic acid |
||||||||
|
2-thienyl mercaptan |
In: Chemistry
Explain anaplerortic reactions and describe the principal such reaction for the CAC and the regulation of its activity in animals
In: Chemistry
at 25 C, a 0.010mol/L ammonia solution is 4.3 percent ionized. Calculate the pH
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Suggest some possibilities as to why your buffer pH might not be exactly 8.0
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4. If you expect the unknown acid molarities to be between 0.010 M and 0.20 M and the sodium hydroxide solution to be 0.050 M, what volume of unknown acid solution would you place into the flask? State your reasoning or assumptions that you make (perhaps typical of those given in question 3, perhaps not) and show your calculation.
Bonus. State two possible errors when using burets that would reduce the accuracy of your titration. Explain specifically whether the result would be a calculated acid molarity that is smaller than the actual value or a calculated acid molarity that is larger than the actual value.
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Briefly discuss the chemistry of the aqua complexes of [Mo3Q4(H2O)9] 4+ (where Q = S or Se).
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For the following reaction, Keq is 0.00183 at 390. K: PCl5(g) PCl3(g) + Cl2(g) If 2.89 g of PCl5 is placed in a 2.86 L bulb at 390. K, what is the equilibrium pressure of Cl2? 1 atm = 1.013 bar
answer in bar
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3) The following “cycle of copper” experiment is performed in some general chemistry laboratories. The series of reactions starts with copper wire and ends with metallic copper. The steps are as follows:
I. A piece of copper wire of known mass is allowed to react with concentrated nitric acid, the products are copper(II) nitrate , nitrogen dioxide, and water.
II. The copper(II) nitrate is treated with a sodium hydroxide solution to form copper(II) hydroxide.
III. On heating, the copper(II) hydroxide decomposes to yield copper(II) oxide.
IV. The copper(II) oxide is combined with concentrated sulfuric acid to yield copper(II) sulfate.
V. Copper(II) sulfate is treated with excess solid zinc metal to form metallic copper.
VI. The remaining zinc metal is treated with hydrochloric acid, and metallic copper is filtered, dried, and weighed.
a. Write a balanced chemical equation for each step. Be sure to pay attention to phase labels.
b. Classify each reaction as a precipitation, acid-base, or redox reaction.
c. Assuming that a student started with 65.6 g of copper, calculate the theoretical yield for each step
In: Chemistry
What are the clear differences in reduction of [Co(NH3)5MoO4] + and [Co(NH3)5CrO4] + by L-ascorbic acid? Would you expect L-ascorbic acid to reduce the Co(III), Cr(VI), and Mo(VI) metal centers when you discuss this interesting chemistry?
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In the reaction of nitrogen gas with oxygen gas to produce nitrogen oxide. What is the effect of adding more nitrogen gas to the initial reaction mixture? N2+O2-2NO. A) the equilibrium shifts to produce more N2 b) the temperature of the reaction is raised c) extra catalyst is required to reach equilibrium d) the equilibrium shifts to produce more NO e) the equilibrium Is not effected
In: Chemistry
(THIS IS A MIXTURE OF ALL OF THE FOLLOWING ACIDS AND BASES MIXED TOGETHER WHERE A COMBINED pH IS WHAT I AM LOOKING FOR)
1. I have 0.500 Liters of water. To that 0.500 Liters, I add the following: a. 0.100 moles HCl b. 0.100 moles HOAc c. 0.100 moles NH4Cl d. 0.100 moles HF e. 0.050 moles NaOH f. 0.050 moles NaOAc g. 0.050 moles Mg(OH)2 What is the pH of the resulting mixture of everything?
Dissociation constants of acids: HOAc Ka=1.78x10-5 H2SO4 Ka1=1x107 Ka2=1.0x10-2 HCNO Ka=2x10-4 H2CO3 Ka1=4.3x10-7 Ka2=5.6x10-11 H2O Ka=1.0x10-14 HIO Ka=2.3x10-11 HNO2 Ka=4.5x10-4 HIO3 Ka = 1.7x10-4 HCl Ka=1x108 HNO3 Ka=1x106 HF Ka = 3.5x10-4 H2C2O4 Ka1 = 6.0x10-2 Ka2 = 6.1x10-5
Dissociation constants of bases: NH3 Kb=1.76x10-5 CH3NH2 Kb=4.4x10-4 NH2OH Kb=1.1x10-8 (CH3)3N Kb=6.5x10-5 C5H5N Kb=1.8x10-9 Mg(OH)2 Kb = 1 x106 NaOH Kb = 1x108
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Raoult's Law describes a simple relationship between the vapor pressure of an ideal solution and the vapor pressure of pure solvent. Non-ideal solutions, however, show deviation from this ideal behavior. Solutions with vapor pressures lower than predicted (negative deviation) are the result of?
In: Chemistry
Mass of flask and foil(g) - 64.5297g
Mass of flask, foil and condensed vapor - 64.9787g
Temperature of boiling water bath - 101.2 C
Volume of flask (mL) - 153.0
Barometric pressure - 762.4 mmHg
Room temp - 23 C
Vapor pressure at room temperature - 100 mmHg
Calculate:
1. Uncorrected mass of condensed vapor(g)
2. Corrected density of air(g/L)
3. Average volume of flask (L)
4. Initial mass of air in flask (g)
5. Final partial pressure of air in flask (mmHg)
6.FInal mass of air in flask (g)
7.Mass of air lost (g)
8. Corrected mass of condensed vapor(g)
9. Molecuular weight (g/mol)
In: Chemistry