The Racah parameter B is 460 cm-1 in [Co(CN)6]3– and 615 cm-1 in [Co(NH3)6]3+. Consider the nature of bonding with the two ligands and explain the difference in the B value.

Explain in cohesive sentences the advantages of LC/MS over GC/MS

Estimate Keq for the following equilibria at 350 K. R = 8.3145 J/(mol*K). Substance ΔHo(kJ/mol) So(J/(mol*K)) SnO2(s) -577.6 49.0 H2(g) 0 130.680 CO(g) -110.5 197.7 Sn(s, white) 0 51.2 H2O(l) -285.83 69.95 Fe(s) 0 27.3 Fe3O4(s) -1118.4 146.4 Correct answer. Correct. SnO2(s) + 2H2(g) ⇄ Sn(s, white) + 2H2O(l) The number of significant digits is set to 2; the tolerance is +/-3% LINK TO TEXT Incorrect answer. Incorrect. 3Fe(s) + 4H2O(l) ⇄ Fe3O4(s) + 4H2(g) Entry field with incorrect answer now contains modified data The number of significant digits is set to 2; the tolerance is +/-3%

Construct flow charts (a.k.a. flow diagrams) to show how to separate each of the following pairs of water insoluble compounds: a) a carboxylic acid and a neutral compound (e.g., a hydrocarbon, R-H); b) a neutral compound and an amine; c) a phenol, a carboxylic acid and an amine (show two different flow charts for separation of this mixture).

Which gas would you expect to behave more like an ideal gas; HCl, H2O, or He? Why?

The bright-red color of highway safety flares comes from strontium ions in salts such as Sr(NO3)2 and SrCO3. Burning a flare produces strontium ions in excited states, which then emit red photons at 606 nm and several wavelengths between 636 and 688 nm. Calculate the energy (in Joules per mole) of the 643 nm emission.

We have a solution of protein that has a concentration of 0.25 mg/ml.

a.We need 20 g of the protein for an experiment. What volume of the protein solution do we need?

b.Suppose we want a solution containing 150 g of the protein at a concentration of 0.50 mg/ml. To do this we will first evaporate the liquid from enough of the protein solution to get 150 g. How much solution do we need to start with? How much H₂O do we add to get the desired concentration?

d.Suppose we want 1 ml of a 10 g/ml solution. How much H₂O and protein stock must we add to get this?

e.Suppose we want 100 l of a 0.1 g/l solution. How much H₂O and protein stock must we add to get this?

A solution of fructose, C₆H₁₂O₆, a sugar found in many fruits, is made by dissolving 38.0 g of fructose in 1.00 kg of water. What is the molal concentration of fructose the solution? What is the mole fraction of fructose in the solution? What is the mass percent of fructose in the solution? What is the molarity of the fructose solution if the density of the solution is 1.0078 g/mL?

Part A

How many milliliters of 0.135  M  HCl are needed to completely neutralize 46.0 mL of 0.101  M  Ba(OH)2 solution?

Part B

How many milliliters of 0.126  M  H2SO4 are needed to neutralize 0.180 g of NaOH?

Part C

If 55.6 mL of BaCl2 solution is needed to precipitate all the sulfate ion in a 758 mg sample of Na2SO4, what is the molarity of the solution?

Part D

If 42.1 mL of 0.204  M  HCl solution is needed to neutralize a solution of Ca(OH)2, how many grams of Ca(OH)2 must be in the solution?

Experiment: Synthesis of Benzoin:

2.6g of thiamine hydrochloride in a flask was dissolved in 8ml of water, 30 ml of ethanol was added and cooled on an ice bath. 5ml of 3M Sodium Hydroxide was added. 15ml of benzaldehyde was added and heated for 1hr.

Question 1:  how would the amount of  of reagents change if the amount of benzaldehyde was reduced to 1 ml. with calculations please?

Question 2: What is the theoretical weight of the product with calculations please?

Concept questions: 1) Acetic acid is a weak acid. Why is a 2M solution of acetic acid less hazardous than a 2M solution of hydrochloric acid? 2) What species must be present in a buffer? Write a chemical reaction that explains how the buffer reacts with acid and then write a chemical reaction that shows how the buffer reacts with base. Wxplain how a buffer works.

H2 + I2 yields 2HI

At the start of the reaction 1 mole of I2 and 1 mole of H2 are put into a 10 liter container. There is no HI present. At the reaction temperature Keq is 64

What is the equilibrium concentrations for H2, I2 and HI?

Would cyclohexanone have 2 or 3 unique hydrogen for H-NMR?

Why are cold solvents preferred during recrystallization and when is recrystallization selected vs other purification techniques?