Calculate the pH during titration of 25 mL of 0.175 M HCN with 0.3 M NaOH after the addition of 0 mL, 7.29mL, 14.5833 mL, and 20 mL base. Show all work.

QUESTION 1

Calculate the mass of SO₃ formed when 9.42 g of SO₂ reacts with 4.50 g of O₂ according to the following reaction.

                      2SO₂ + O₂ → 2SO₃

QUESTION 2

If 12.002g of potassium oxalate hydrate is added to a beaker and then 20mL of DI water is added to dissolve and then 8.0mL of 1.5 M FeCl₃ is added. Which statement is correct

QUESTION 3

The reaction of 35.0 g of Al with excess g of Cr₂O₃ produced 25.6 g of Cr. What is the percent yield for this reaction?

                      2Al + Cr₂O₃ → Al₂O₃ + 2Cr

QUESTION 4

Chlorine gas can be made from the reaction of manganese dioxide with hydrochloric acid.

                      MnO₂(s) + 4HCl(aq) → MnCl₂(aq) + 2H₂O(l) + Cl₂(g)

            According to the above reaction.

If 1.5 moles of MnO₂ are reacted with 5.6 moles of HCl which of the following statements is true?

For the reactions shown below, we added 2.25 mL of 0.0450 M HCl to a test tube containing one of the two cations (Ag⁺ or Pb²⁺) and recovered 0.0141 g of precipitate.

AgNO₃(aq) + HCl(aq) → AgCl(s) + HNO₃(aq)
Pb(NO₃)₂(aq) + 2 HCl(aq) → PbCl₂(s) + 2 HNO₃(aq)

How much precipitate in moles would be recovered theoretically if the ion was Ag⁺? (Enter an unrounded value. Use at least one more digit than given.)
mol

How much precipitate in moles would be recovered theoretically if the ion was Pb²⁺? (Enter an unrounded value. Use at least one more digit than given.)
mol

How much precipitate in grams would be recovered theoretically if the ion was Ag⁺?
g

How much precipitate in grams would be recovered theoretically if the ion was Pb²⁺?

g

Based on the precipitate amount recovered, which of the two ions was in the unknown?

Ag⁺

Pb²⁺  

Calculate the equilibrium concentration of undissociated in a glycolic acid solution with an analytical glycolic acid concentration of 0.0824 and a pH of 3.180.

Do you predict that maltose will reduce cupric ion in Fehling

For the reactions shown below, we added 3.75 mL of 0.0450 M Na₂S to a test tube containing one of the two cations (Cu²⁺ or Cd²⁺) and recovered 0.0161 g of precipitate.

Cu(NO₃)₂(aq) + Na₂S(aq) → CuS(s) + 2 NaNO₃(aq)
Cd(NO₃)₂(aq) + Na₂S(aq) → CdS(s) + 2 NaNO₃(aq)

How much precipitate in moles would be recovered theoretically if the ion was Cu²⁺? (Enter an unrounded value. Use at least one more digit than given.)
mol

How much precipitate in moles would be recovered theoretically if the ion was Cd²⁺? (Enter an unrounded value. Use at least one more digit than given.)
mol

How much precipitate in grams would be recovered theoretically if the ion was Cu²⁺?
g

How much precipitate in grams would be recovered theoretically if the ion was Cd²⁺?

g

Based on the precipitate amount recovered, which of the two ions was in the unknown?

Cu²⁺

Cd²⁺

Calculate the nuclear binding energy in mega-electronvolts (MeV) per nucleon for 179Hf if its nuclear mass is 178.946 amu.

A 67.2 g sample of a gold and palladium alloy contains 2.85×1023 atoms . What is the mass percentage of the gold and palladium?

for the titration of 10.0 ml of .15 M HNO2 aqueous solution (Ka=7.2x10^-4) using 2.5 M NaOH aqueous solution, consider the following points of the titration: A: Initial pH of .15 M HNO2 aqueous solution B: .1 mL added base C: 1/2 equivalence point D: Equivalence point E Excess base (assume added 100.0 mL of base)

Set up the init mol, final mol, total volume, and ICE table for points B and D only:

Point B:

Titration equation:

init mol:

(assume reaction goes to completion)

final mol:

total volume:

flip reaction equation:

I:

C:

E:

Point D:

Titration equation:

init mol:

(assume reaction goes to completion)

final mol:

total volume:

flip reaction equation:

I:

C:

E:

Molar solubility of copper hydroxide in pure water, taken into account that water is adding hydroxide into the solution. Ksp=[Cu^2+][OH^-]^2 = 4.8x10^-20

(x) (1.0x10^-7 +2x)^2 = 4.8x10^-20

1. Why is that during alpha emission, the atomic number decreases by two, and the mass number decreases by four? In your answer yu should consider what alpha particle is?

2. In beta emission, the atom loses an electron, yet the atomic increase by one and the mass number stays the same. How is this possible? It may help if you consider what happen to the number of neutrons and protons.

3. if an element is bombarded by an neutron and subsequently emits a gamma ray, then it follows that the mass number will increase by one. How is it then, the atomic number remains unchanged?

Part A

A 3.00-L flask is filled with gaseous ammonia, NH3. The gas pressure measured at 25.0 ∘C is 2.05 atm . Assuming ideal gas behavior, how many grams of ammonia are in the flask?

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

Part B

If 1.00 mol of argon is placed in a 0.500-L container at 28.0 ∘C , what is the difference between the ideal pressure (as predicted by the ideal gas law) and the real pressure (as predicted by the van der Waals equation)?

For argon, a=1.345(L2⋅atm)/mol2 and b=0.03219L/mol.

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

Discuss the thermodynamic driving force of micelles and bilayer membranes.

What is the limiting reagent in esterification using isopentyl alcohol and acetyl chloride to make isopentyl acetate? Prove your answer with limiting reagent calculations.

Used 200 uL of isopentyl alcohol, 800 uL of acetyl chloride in the experiment.