The acid ionization constant for Ga(H2O)63+ (aq) is 2.5×10-3 . Calculate the pH of a 0.1500 M solution of Ga(NO3)3 .

Acid HX is a weak acid with K_a=1.0x10^-6. A 50.0 mL sample of 1.00 M HX(aq) is titrated with 1.00 M NaOH(aq). What is the pH of the solution at the points listed below during titration?

A. pH 1.00M HX solution before titration:

B. pH after 25.0mL 1.00M NaOH added:

Please show work! Thank you!

Please Give All 3 answer.

Q1) A student was given a sample of crude salicylic acid to recrystallize. The initial mass of the crude acid was 131 mg. The mass after recrystallization was 121 mg. Calculate the percent recovery from recrystallization.

Q2) If 91.0 g of oxalic acid and 79.0 g of methanol react to form 89.0 g of dimethyl oxalate and water, what is the percent yield?

Q3) A student measures out exactly 0.109 g of salicylic acid and runs the experiment as dictated in the lab manual. They obtain 0.101 g of aspirin. What is the percent yield for their reaction?

pMice that are completely lacking the Adenine nucleotide translocase gene (Ant-/-) are viable (which is surprising) and show the following physiological phenotypes:

nHighlevels of alanine, lactate and succinate (in serum).

nAsix-fold increase of mitochondrial hydrogen peroxide as compared with normal control mice.

pGive reasonable biochemicalexplanations to each of these observations.

Calculate the concentrations of all species in a 0.540 M Na2SO3 (sodium sulfite) solution. The ionization constants for sulfurous acid are Ka1 = 1.4× 10–2 and Ka2 = 6.3× 10–8.

Chlorine can be prepared in the laboratory by the reaction of manganese dioxide with hydrochloric acid, HCl(aq), as described by the chemical equation: MnO2(s) + 4HCl --> MnCl2 (aq) + 2H2O (l) + Cl2 (g) How much MnO2(s) should be added to excess HCl(aq) to obtain 405 mL of Cl2(g) at 25 �C and 805 Torr?

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

a.		22.52 g
	b.	11.77 g
c.		11.25 g
	d.	34.27 g
	e.	5.63 g

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

	a.	the beaker contains 0.173 moles of potassium oxalate hydrate and 0.012 moles of iron(III) chloride
	b.	the beaker contains 0.0651 moles of potassium oxalate hydrate and 0.012 moles of iron(III) chloride
	c.	the beaker contains 3.255 moles of potassium oxalate hydrate and 0.012 moles of iron(III) chloride
	d.	the beaker contains 0.012 moles of potassium oxalate hydrate and 0.0651 moles of iron(III) chloride
	e.	the beaker contains 3.255 moles of potassium oxalate hydrate and 12.0 moles of iron(III) chloride

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

	a.	51.0%
	b.	196.3%
	c.	73.1%
	d.	75.9%
	e.	37.9%

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?

a.		HCl is the limiting reactant and 11.2 mol of water is produced
b.		HCl is the limiting reactant and 2.8 mol of water is produced
c.		MnO2 is the limiting reactant and 3.0 mol of water is produced
d.		HCl is the limiting reactant and 5.8 mol of water is produced
e.		MnO2 is the limiting reactant and 5.8 mol of water is produced

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: