Give the values of the quantum numbers ( n, l, ml, ms) associated with the following orbitals: 2p spin up, 3s spin up, 5d spin up.
In: Chemistry
A certain chemistry instructor felt that there were some "dry-labbers" in the chemistry course. ["Dry-labbers" think they know the answer to a lab experiment, and give their expected answer without doing the experiment--which isn't fair to the others in the lab!] So, all students in the lab were asked to determine the boiling point of pure water contained in a flask labeled "pure water." The "pure water" was actually a very concentrated calcium dichloride solution. Three students were caught not actually doing the experiment and given F's for their experiment. Explain how the chemistry instructor was able to catch the dishonest "dry-labbers."
In: Chemistry
According to the textbook: “lectin and glycan arrays provide a platform to screen large number of samples for specific binding interactions using fluorescently labeled molecules. Two basic types of arrays have been developed for screening purposes: (1) protein arrays containing covalently attached lectin proteins or antibodies for the detection of labeled glycoproteins in experimental samples; and (2) glycan arrays containing covalently attached glycoproteins with intact glycan groups (or chemically synthesized glycan groups) for the detection of labeled lectin proteins or antibodies in experimental samples. Pick one type of array. Explain one advantage and one disadvantage to this type of glycan analysis. Find a method that has been developed to overcome the disadvantage that you listed and briefly explain how it works.
In: Chemistry
determine the miller indice of the plane comprised of the following coordinates: (1/2,0,1/2) (0,0,1) (1,1,1)
In: Chemistry
A reaction was run and found to have a half life that got shorter as the initial concentration of the reactant ([A]) was increased. When the reaction was run at two different temperatures, the following data sets were generated.
| At 530 K | At 940 K | ||
| [A] | Time (sec.) | [A] | Time (sec.) |
| 0.285 | 0.00 | 0.285 | 0.00 |
| 0.0596 | 255.0 | 0.000551 | 14.0 |
| 0.0295 | 585.0 | 0.000221 | 35.0 |
| 0.0170 | 1065.0 | 0.000164 | 47.0 |
| 0.00637 | 2950 | 5.72e-05 | 135.0 |
Use the data given to determine the value of k (the rate constant) at each temperature, and then determine the Energy of Activation for this reaction.
k at 530 K = ??? 1/Msec
k at 940 K = ??? 1/Msec
Ea = ??? kJ/mol
In: Chemistry
Professor Modyn owns a device called a pneumatic accumulator. This device maintains constant pressure of 217.00 psia as air enters by using a piston. Initially the device is filled with air at 76.74 °F and the volume is 0.317 ft3 (State 1). Air at 191.2 °F and 217.00 psia is fed into the accumulator until the volume triples and the temperature increases to 181.2 °F (State 2). Assume air is an ideal gas with a CP = 3.5R and MW = 29. No air leaves the system.
a) Find the amount of air added. (lbmol)
b) Calculate the work interaction term. (ft*lbf)
c) Calculate the heat interaction term. (ft*lbf)
In: Chemistry
A mixture is prepared that has 0.5276 g of solute in 9.9022g of cyclohexane. The freezing point temperature change is found to be 5.4 degree C. The percent composition of the solute is: 93.7% C, and 6.30% H.
a. find the empirical formula of the solute.
b. find the empirical mass of the solute.
c. find the molar mass of the solute.
d. find the molecular formula of the solute.
In: Chemistry
column chromatography
Why do you begin with a nonpolar solvent and continually increase polarity instead of the other way around?
. Are the factors controlling the movement of the compounds the same for TLC as they are for column chromatography? Briefly, why or why not?
. what would you change to make for a more efficient separation.
In: Chemistry
Problems by Topic - The Common Ion Effect and Buffers
Solve an equilibrium problem (using an ICE table) to calculate the pH of each of the following.
(1) a solution that is 0.17 M in HCHO2 and 0.11 M in NaCHO2
(2) a solution that is 0.12 M in NH3 and 0.16 M in NH4Cl
2nd set of problems
Part A
Use the Henderson-Hasselbalch equation to calculate the pH of a solution that is 0.110 M in HClO and 0.155 M in KClO.
Part B
Use the Henderson-Hasselbalch equation to calculate the pH of a solution that is 0.180 M in C2H5NH2 and 0.155 M in C2H5NH3Br.
Part C
Use the Henderson-Hasselbalch equation to calculate the pH of a solution that is 10.5 g of HC2H3O2 and 13.5 g of NaC2H3O2 in 150.0 mL of solution.
In: Chemistry
Why my percentage yield is much less than 100%?
what couze that ?
In: Chemistry
Determine the percent ionic charcter of the following bonds, based on the electronegativity differences: Show your work.
a. NaCl
b. FeCl2
c. CuCl
d. AlCl3
e. CCl4
In: Chemistry
Calculate the mass of sodium acetate trihydrate required to make 100. mL of a 0.100 M solution.
In: Chemistry
Sulfuric acid dissolves aluminum metal according to the following reaction: 2Al(s)+3H2SO4(aq)?Al2(SO4)3(aq)+3H2(g) Suppose you wanted to dissolve an aluminum block with a mass of 14.7g .
Part A
What minimum mass of H2SO4 would you need?
Express your answer in grams.
Part B
What mass of H2 gas would be produced by the complete reaction of the aluminum block?
Express your answer in grams.
In: Chemistry
Why is a Diels-Alder reaction favored at lower temperature? Please give a clear and specific answer.
In: Chemistry
calculate the concentrations of H+, HCO- and CO3^2- in a 0.025 M H2CO3 solution
In: Chemistry