Calculate the pH of a 0.100M NaCH₃COO solution. Ka for acetic acid, HC₂H₃O₂ is 1.8x10^-5

From the equilibrium concentrations given, calculate Ka for each of the weak acids and Kb for each of the weak bases.

c) HCO2H

[HCO2H]= 0.524 M

[H3O+]= 9.8 x 10^-3 M

[HCO2-] 9.8 x 10^-3

d) C6H5NH3+

[C6H5NH3+]= 0.233

[C6H5NH2]= 2.3 x 10^-3

[H3O+]= 2.3 x 10^-3

A 5.00 ml sample of blood was treated with trichloroacetic acid to precipitate proteine. After centrifugation, the resulting solution was brought to a PH of 3 and was extracted with two 5-ml, portions of methyl isobutyl ketone containing the organic lead complexing agent APCD. The extract was aspirated directly into an air-acetylene flame yielding an absorbance of 0.444 at 283.3nm. Five-milliliter aliquots of standard solutions containing 0.250 and 0.450ppm BP were treated in the same way and yielded absorbances of 0.396 and 0.599. Calculate the concentration(ppm) in the sample assuming that Beer's law is followed

How many mL of 0.200 M HBr acid would be needed to neutralize 50.0 grams of calcium hydroxide solid that is completely dissolved in enough water to make 500. mL of solution?

In the laboratory you dissolve 18.6 g of potassium carbonate in a volumetric flask and add water to a total volume of 500 mL.  

What is the molarity of the solution?   M.

What is the concentration of the potassium cation?   M.

What is the concentration of the carbonate anion?   M.

Ammonia gas enters the reactor of a nitric acid plant mixed with 30% more dry air than is required for the complete conversion of the ammonia to nitric oxide and water vapor. If the gases enter the reactor at 75 ◦ C (167 ◦ F), if conversion is 80%, if no side reactions occur, and if the reactor operates adiabatically, what is the temperature of the gases leaving the reactor? Assume ideal gases.

the protein xpot transports all tRNAs out of the nucelus so that they can be aminoacylated in the cytosol.

a) What tRNA structural feature is Xpot likely to recognize?
b) Why might it be beneficial for aminoacylation to occur in the cytosol?

A method for determination of the second virial coefficient of a pure gas is based on the Clapeyron equation and measurements of the latent heat of vaporization (ΔH^lv), the molar volume of saturated liquid (V^l), and the vapor pressure (P^sat). Determine B in cm³/mol for methyl ethyl ketone at 75^oC from the following data at this temperature:

ΔH^lv=31,600 J/mol, V^l = 96.49 cm³/mol

ln(P^sat)=48.157543-5622.7/T^_ 4.70504 ln(T) T(K), P^sat (kPa)

You are an experimental psychologist interested in finding out how effective a new medication might work for treating depression. Describe a study you might conduct to reach some conclusions on this matter. Be sure to define and provide examples of the following terms and concepts, demonstrating your understanding of each: hypothesis, independent variable, dependent variable, random assignment of participants, ethical guidelines.

Calculate the pH of the solution after the addition of the following amounts of 0.0615 M HNO3 to a 50.0 mL solution of 0.0750 M aziridine. The pKa of aziridinium is 8.04.

a) 0.00 mL of HNO3

b) 9.69 mL of HNO3

c) Volume of HNO3 equal to half the equivalence point volume

d) 57.1 mL of HNO3

e) Volume of HNO3 equal to the equivalence point

f) 65.3 mL of HNO3

Calculate the pH after 0.16 mole of NaOH is added to 1.10 L of a solution that is 0.58 M HCO2H and 1.12 M HCO2Li, and calculate the pH after 0.32 mole of HCl is added to 1.10 L of the same solution of HCO2H and HCO2Li.

0.16 mole of NaOH

0.32 mole of HCl

Useful Information: The 25.0 wt % ethylenediamine solution contains 25.0 % ethylenediamine by mass, dissolved in water, and has a density of 0.950 g/mL. First calculate the mass of the C2H8N2 solution from its volume and density, then calculate the mass of the C2H8N2 by remembering that
mass of solute wt % solution = x 100 mass of solution
From their masses and formula weights, you should then compute the number of moles of NiCl2•6H2O and of C2H8N2 that were used. (Remember the formula weight of NiCl2•6H2O should include the mass of the waters of hydration.)  

1. Create a typed table that concisely presents the quantities (mass or volume as appropriate for each reagent, as well as moles for all reagents) and appearance of both of the reactants and the nickel product. (Remember to clearly label the table with a title and headers for all data columns/ rows. Avoid blank cells in the table.)

2. What was the limiting reactant for your synthesis? Show your typed calculations. 3. What was the theoretical and percent yield of trisethylenediaminenickel(II) chloride for your experiment? Show your typed calculations.

4. Assuming all of the limiting reactant was completely consumed (reacted), how many moles of the other reactant (non-limiting) remained? Show your typed calculations.

Consider the following two solvents

Solubility

Solvent A 52g of product in 100mL at 100 celcius; 29g of product in 100mL at 25 celcius

Solvent B 8.1g of product in 100mL at 100 celcius; 0.91g of product in 100mL at 25 celcius

(a) Which solvent is a good crystallization solvent for the product? Explain your reasoning.

(b) If a student started out with 2.5021g of crude product, what will be the % yield after one crystallization step by using the minimum amount of solvent A that is required for the crystallization step?

(c) If a student started out with 2.5021g of crude product, what will be the % yield after one crystallization step by using the minimum amount of solvent B that is required for the crystallization step?

a strip of Ag was placed in a beaker containing 1.0 M AgNO3, and a strip of Co was put in a second beaker containing Co(NO3)2. The silver and cobalt electrodes were connected by a wire through an ammeter, and the two beakers were connected by a NaCl salt bridge.

1. Use E0 valuesto describe which way the electrons will flow. Show the direction of electron flow on the diagram, then label the anode and the cathode.Ag+ + e- = Ag (s) E0=0.80;

Co2++2 e- = Co (s) E0=-0.28

2. write and label the oxidation and reduction half-reactions that will be occuring if the electrons are flowing in the direction shown on your diagram. Show the final balanced equation.

3. Use the above 1/2 reaction to find the maximum total E0 valune for the entire cell.

4. Explain in detail what the sodium and chlorine ions in the salt bridge are doing and why they must do this.

5. What happens to the voltage of the cell as equilibrium is approached?

6. What voltage would have to be applied from another battery to make the cell run in reverse?