How would you prove that a silica microsphere made by the Stobber process is actually spherical? What affect might deviations from an exact spherical shape have on crystallizing opals and their optical properties?

60.0 mL of 0.100M KOH(aq) is mixed with 40.0 mL of 0.250M HCl(aq) at 25 oC. Assuming that volumes are additive, the pH of resulting solution is

What is the pH for a 400 ml solution of 1.6 M Benzoic Acid?

If you added 75 grams of conjugate base (NaC6H5CO2) to the solution, what would the new pH be?

If you now added 75 ml of 1.35 M NaOH, what would be the new pH?

3.  (15 pts) For the following calibration techniques:  (a) Standard addition, (b) External calibration, and (c) Internal calibration:  Draw a picture of what each graph would look like, describe each technique, and give a reason why each might be used for quantification (an advantage of each).

*just wants a general example plot, not data is provided for this problem.*

typing only...

Describe how nitrogen can be separated from the other components of air.

8H2S(g)+4O2(g)→8H2O(g)+S8(g) Δ[H2S]/Δt = -0.012 M/s

a)Find Δ[O2]/Δt.

b)Find Δ[H2O]/Δt.

c)Find Δ[S8]/Δt.

d)Find the rate of the reaction.

What are the experimental procedures for conducting a standard addition method in analytical chemistry. Why such a method is so popular in complex sample analysis? Use equations and plots and figures to explain hoy the unknown concentration is obtained from the measured data.

A student is asked to determine how many different dyes a water-soluble food coloring contains. Which technique is best suited to this task?
     (A) paper chromatography
     (B) distillation
     (C) column chromatography
     (D) filtration

1.00atm of H2 and 1.00atm of Br2 were mixed in a 1.00L flask at 25°C. Under the appropriate conditions, gaseous HBr will form. At equilibrium, 1.10×10^13 molecules of H2 were found. Given the information below, calculate the values of K, delta G°, and delta S°. (for this problem, you do not have available values of free energies of formation and values of entropies of formation.)
H2(g) + Br2(g) ----> 2HBr(g)   delta H°= -103.8kJ

Discuss the results and observations of the data obtained for each acid. Specifically, discuss how the equivalence point volumes obtained from the different graphs compare to each other and to the endpoint volume determined from the indicator color change. Also, comment on why so many different means of determining the endpoint volume are necessary. Under what circumstances would one be better than another? Compare your Ka to that reported in the textbook and discuss any discrepancies

the experiment was titration of HCL and NaOH and then determining the equivalence point and the endpoint using a different method

Analysis of the Acid using Different Methods

A fuel gas containing 77% methane, 7% ethane and rest propane by volume. The fuel flows to a combustion chamber at the rate of 1321 m^3/h at 15C and 150 kPA (gauge) where it is burned with 8% excess air entering at 20C. ROund your answer to the nearest whole number.

a) WHat is the propane percent in the fuel gas?

b) What is the actual number of moles of fuel flowing into the combustion chamber?

c) What is the actual number of moles of oxygen flow into the combustion chamber?

d) What is the actual number of moles of air flowing into the combustion chamber?

e) What is the ACMH?

1) The boiling point of an aqueous solution is 101.98 ∘C. What is the freezing point? Consult the table of colligative constants.

freezing point:   °C

2)

Quinine is a natural product extracted from the bark of the cinchona tree, which is native to South America. Quinine is used as an antimalarial agent.

When 0.829 g of quinine is dissolved in 25.0 g of cyclohexane, the freezing point of the solution is lowered by 2.13 ∘C. Look up the freezing point and Kf constant for cyclohexane in the Colligative Constants table.

Calculate the molar mass of quinine.

molar mass:

g/mol

3)

If a 0.770 m aqueous solution freezes at −2.30 ∘C, what is the van't Hoff factor, i, of the solute?

Consult the table of K_f values.

i=

Consider the following reaction:

A(g)⇌2B(g)

Find the equilibrium partial pressures of A and B for each of the following different values of Kp. Assume that the initial partial pressure of B in each case is 1.0 atm and that the initial partial pressure of A is 0.0 atm. Make any appropriate simplifying assumptions.

Kp = 2.0?

Kp = 1.4 x 10^4?

Kp = 1.2 x 10^5?

When 22.0 mL of a 2.08×10^-4M ammonium iodide solution is combined with 18.0 mL of a 5.92×10^-4M lead acetate solution does a precipitate form? _____ (yes or no)

For these conditions the Reaction Quotient, Q, is equal to _____