Preparing Buffer Solutions: Calculating the Number of Grams of Conjugate Base Needed

Use the table of K values given with this problem to choose the best weak acid to start from for making a buffer that holds the pH of the solution at 3.20. Make your selection so that you maximize the capacity of the buffer.
You select a 200.0 ml volumetric flask to which you add 54.00 mL of a 2.90 M solution of the weak acid you just selected. To finish preparing your buffer you must now add the sodium salt of the conjugate base. How many grams of the sodium salt of your conjugate base must you add so that when you finally fill the flask to the mark with deionized water the buffer will have a pH of 3.20.

I posted this question before and they got the answer of 8.00g which is NOT CORRECT, so I was looking someone else to help me with this.

In my lab we found OUR average molarity to be 0.83334 M, but we used 3% H2O2 (hydrogen peroxide), so I'm not sure how to do this or what numbers to even use.

7. Convert the average molarity of hydrogen peroxide into % (wt) of hydrogen peroxide (the density of the solution = 1.009g/ml).

8. Comparing the above calculated % of hydrogen peroxide with the known (labeled on the bottle) value, calculate the % experimental error.

The first four peaks in the X-ray powder diffraction pattern of sodalite are at 2 values of 9.97°, 14.12°, 17.32° and 20.02°. The radiation used for the experiment was Cu K with  = 1.5418 Å. Determine the lattice type and calculate the length, a, of the cubic unit-cell.

FeS can be roasted in O 2 to form FeO, according to the reaction 2FeS + 3O 2 2FeO + 2SO 2 If the slag (solid product) contains 80% FeO and 20% FeS , and the exit gas is 100% SO 2 , determine the extent of reaction and the initial moles of FeS. Use 100 lb as the basis. [0.557; 1.341 lb-mol]

A sample is analyzed to determine its iron content Fe2+ via a redox titration with potassium chromate as the titrant. In the titration Fe2+ is oxidized to Fe3+ and CrO4 2- is reduced to Cr 3+. What is the percent by mass of iron in the sample if 0.9087g of the sample required 45.68mL of a 0.04322 M K2CrO4 solution to reach the endpoint?

I worked out the balanced equation to be:

8H+ + 3Fe2+ + CrO4 2- = 3Fe3+ + Cr3+ + 4H2O

What is the mechanism by which solute is dissolved in non polar solvents? Explain briefly. (5 mark)

Part B What mass of carbon dioxide is produced from the complete combustion of 6.90×10−3 g of methane? Express your answer with the appropriate units.

Part C What mass of water is produced from the complete combustion of 6.90×10−3 g of methane? Express your answer with the appropriate units. Part D What mass of oxygen is needed for the complete combustion of 6.90×10−3 g of methane? Express your answer with the appropriate units   

The equilibrium constant for the reaction of fluorine gas with bromine gas at 300 K is 54.7 and the reaction is: Br2(g) + F2(g) ⇔ 2 BrF(g) What is the equilibrium concentration of fluorine if the initial concentrations of bromine and fluorine were 0.121 moles/liter in a sealed container and no product was present initially?

In each pair, indicate which substance has the stronger intermolecular forces and explain your reasoning: (a) Ne, Ar; (b) NF3, BF3; (c) SiH4, GeH4; (d) NaF, HF.

1. Calculate the dilution factor and final concentration of the following target analytes:

20 mL of target analyte (2.5 M), to a final volume of 100 mL

2 mL of target analyte (3.23 ppm), to a final volume of 0.05 L.

5 mL of target analyte (15.9032 %), to a final volume of 1 dL.

1 dL of target analyte (4.0989 M), to a final volume of 0.25 L

0.025 L of target analyte (1.8982 g / L), to 79 g of ethanol.

10 mL of target analyte (2.0902 g / L), to 66.5 g of dichloromethane.

A solution containing a mixture of metal cations was treated with dilute HCl and a precipitate formed. The solution was filtered and H2S was bubbled through the acidic solution. A precipitate again formed and was filtered off. Then, the pH was raised to about 8 and H2S was again bubbled through the solution. This time, no precipitate formed. Finally, the solution was treated with a sodium carbonate solution, which resulted in formation of a precipitate. Which metal ions were definitely present, which were definitely absent, and which may or may not have been present in the original mixture? Ag+, Zn2+, Co2+, Li+, Cu2+, Ca2+, Fe2+, Sn2+, Mg2+, Hg22+ Sb3+, Hg2+, Pb2+

1. Add the periodic trend of electronegativity to your periodic table.
2. On your periodic table underline the elements that make up the 7 diatomic molecules (from chapter 6.6) and add the periodic trends of ionization energy, atomic size, and metallic character (chapter 4.8).

Please explain...

In the titration of a weak acid HA with 0.100 M NaOH, the stoichiometric point is known to occur at a pH value of approximately 11. Which of the following indicators would be best to use to mark the endpoint of this titration?

a. an indicator with Ka = 10–13

b. an indicator with Ka = 10–14

c. an indicator with Ka = 10–10

d. an indicator with Ka = 10–8

e. an indicator with Ka = 10–11

An indicator HIn has Ka = 1 × 10–8. At pH = 6.0, what is the ratio HIn/In– ?

a. 1/100

b. 10/1

c. 1/1

d. 100/1

e. none of these

balance redox reaction that occurs in acidic conditions. what are coefficients for H + & Fe3+ once reaction is balanced? write it as H+=#; Fe +3 = #

Fe2+(aq)+Mn04-(aq) -> Fe3+(aq)+Mn2+(aq)