Suggest some possibilities as to why your buffer pH might not be exactly 8.0

4. If you expect the unknown acid molarities to be between 0.010 M and 0.20 M and the sodium hydroxide solution to be 0.050 M, what volume of unknown acid solution would you place into the flask? State your reasoning or assumptions that you make (perhaps typical of those given in question 3, perhaps not) and show your calculation.

Bonus. State two possible errors when using burets that would reduce the accuracy of your titration. Explain specifically whether the result would be a calculated acid molarity that is smaller than the actual value or a calculated acid molarity that is larger than the actual value.

Briefly discuss the chemistry of the aqua complexes of [Mo3Q4(H2O)9] 4+ (where Q = S or Se).

For the following reaction, Keq is 0.00183 at 390. K: PCl5(g) PCl3(g) + Cl2(g) If 2.89 g of PCl5 is placed in a 2.86 L bulb at 390. K, what is the equilibrium pressure of Cl2? 1 atm = 1.013 bar

answer in bar

3) The following “cycle of copper” experiment is performed in some general chemistry laboratories. The series of reactions starts with copper wire and ends with metallic copper. The steps are as follows:

I. A piece of copper wire of known mass is allowed to react with concentrated nitric acid, the products are copper(II) nitrate , nitrogen dioxide, and water.

II. The copper(II) nitrate is treated with a sodium hydroxide solution to form copper(II) hydroxide.

III. On heating, the copper(II) hydroxide decomposes to yield copper(II) oxide.

IV. The copper(II) oxide is combined with concentrated sulfuric acid to yield copper(II) sulfate.

V. Copper(II) sulfate is treated with excess solid zinc metal to form metallic copper.

VI. The remaining zinc metal is treated with hydrochloric acid, and metallic copper is filtered, dried, and weighed.

a. Write a balanced chemical equation for each step. Be sure to pay attention to phase labels.

b. Classify each reaction as a precipitation, acid-base, or redox reaction.

c. Assuming that a student started with 65.6 g of copper, calculate the theoretical yield for each step

What are the clear differences in reduction of [Co(NH3)5MoO4] + and [Co(NH3)5CrO4] + by L-ascorbic acid? Would you expect L-ascorbic acid to reduce the Co(III), Cr(VI), and Mo(VI) metal centers when you discuss this interesting chemistry?

In the reaction of nitrogen gas with oxygen gas to produce nitrogen oxide. What is the effect of adding more nitrogen gas to the initial reaction mixture? N2+O2-2NO. A) the equilibrium shifts to produce more N2 b) the temperature of the reaction is raised c) extra catalyst is required to reach equilibrium d) the equilibrium shifts to produce more NO e) the equilibrium Is not effected

(THIS IS A MIXTURE OF ALL OF THE FOLLOWING ACIDS AND BASES MIXED TOGETHER WHERE A COMBINED pH IS WHAT I AM LOOKING FOR)

1. I have 0.500 Liters of water. To that 0.500 Liters, I add the following: a. 0.100 moles HCl b. 0.100 moles HOAc c. 0.100 moles NH4Cl d. 0.100 moles HF e. 0.050 moles NaOH f. 0.050 moles NaOAc g. 0.050 moles Mg(OH)2 What is the pH of the resulting mixture of everything?

Dissociation constants of acids: HOAc Ka=1.78x10-5 H2SO4 Ka1=1x107 Ka2=1.0x10-2 HCNO Ka=2x10-4 H2CO3 Ka1=4.3x10-7 Ka2=5.6x10-11 H2O Ka=1.0x10-14 HIO Ka=2.3x10-11 HNO2 Ka=4.5x10-4 HIO3 Ka = 1.7x10-4 HCl Ka=1x108 HNO3 Ka=1x106 HF Ka = 3.5x10-4 H2C2O4 Ka1 = 6.0x10-2 Ka2 = 6.1x10-5

Dissociation constants of bases: NH3 Kb=1.76x10-5 CH3NH2 Kb=4.4x10-4 NH2OH Kb=1.1x10-8 (CH3)3N Kb=6.5x10-5 C5H5N Kb=1.8x10-9 Mg(OH)2 Kb = 1 x106 NaOH Kb = 1x108

Raoult's Law describes a simple relationship between the vapor pressure of an ideal solution and the vapor pressure of pure solvent. Non-ideal solutions, however, show deviation from this ideal behavior. Solutions with vapor pressures lower than predicted (negative deviation) are the result of?

Mass of flask and foil(g) - 64.5297g

Mass of flask, foil and condensed vapor - 64.9787g

Temperature of boiling water bath - 101.2 C

Volume of flask (mL) - 153.0

Barometric pressure - 762.4 mmHg

Room temp - 23 C

Vapor pressure at room temperature - 100 mmHg

Calculate:
1. Uncorrected mass of condensed vapor(g)

2. Corrected density of air(g/L)

3. Average volume of flask (L)

4. Initial mass of air in flask (g)

5. Final partial pressure of air in flask (mmHg)

6.FInal mass of air in flask (g)

7.Mass of air lost (g)
8. Corrected mass of condensed vapor(g)
9. Molecuular weight (g/mol)

Calculate the percent ionization of 8.0

Why does the antifreeze ethylene glycol, HO-CH2-CH2-OH, molar mass 62.07 g/mol, have a much higher higher boiling point (197.6°C) than propanol (97.4°C), CH3-CH3-CH2-OH, molar mass 60.09 g/mol, even though they have similar molar masses?

As a technician in a large pharmaceutical research firm, you need to produce 450. mL of a potassium dihydrogen phosphate buffer solution of pH = 6.91. The pKa of H2PO4− is 7.21. You have the following supplies: 2.00 L of 1.00 M KH2PO4 stock solution, 1.50 L of 1.00 M K2HPO4 stock solution, and a carboy of pure distilled H2O. How much 1.00 M KH2PO4 will you need to make this solution? (Assume additive volumes.)

What is the Henry's law constant for CO2 at 20∘C?

Express your answer to three significant figures and include the appropriate units.

What pressure is required to achieve a CO2 concentration of 9.40×10⁻² M at 20∘C?

Express your answer to three significant figures and include the appropriate units.

At 1 atm, how many moles of CO2 are released by raising the temperature of 1 liter of water from 20∘C to 25∘C?

Express your answer to four decimal places and include the appropriate units.

The Ostwald process is used commercially to produce nitric acid, which is, in turn, used in many modern chemical processes. In the first step of the Ostwald process, ammonia is reacted with oxygen gas to produce nitric oxide and water. \(4NH_{3}(g)+5O_{2} --> 4NO+6H_{2}O(g)\) What is the maximum mass of H2O that can be produced by combining 72.0 g of each reactant?