Using Kröger-Vink notation, write the defect chemical equation for mixing FeO into Fe₂O₃

Aluminum reacts with chlorine gas to form aluminum chloride via the following reaction:

2Al(s)+3Cl2(g)→2AlCl3(s)

What is the maximum mass of aluminum chloride that can be formed when reacting 15.0g of aluminum with 20.0 g of chlorine?

A.) Calculate the enthalpy change, ΔH, for the process in which 37.9 g of water is converted from liquid at 4.6 ∘C to vapor at 25.0 ∘C .

For water, ΔHvap = 44.0 kJ/mol at 25.0 ∘C and Cs = 4.18 J/(g⋅∘C) for H2O(l).

B.)How many grams of ice at -29.4 ∘C can be completely converted to liquid at 20.7 ∘C if the available heat for this process is 5.90×10³ kJ ?

For ice, use a specific heat of 2.01 J/(g⋅∘C) and ΔHfus=6.01kJ/mol.

C.)In the following experiment, a coffee-cup calorimeter containing 100 mL of H2O is used. The initial temperature of the calorimeter is 23.0 ∘C. If 4.20 g of CaCl2 is added to the calorimeter, what will be the final temperature of the solution in the calorimeter? The heat of solution ΔHsoln of CaCl2 is −82.8 kJ/mol.

D.)

Calculate the standard enthalpy change for the reaction

2A+B⇌2C+2D

Use the following data:

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

Could I have the explanations for the respective questions?

Use these answers for questions 8 - 10.

(A) a solution with a pH less than 7 that is not a buffer solution

(B) a buffer solution with a pH between 4 and 7

(C) a buffer solution with a pH between 7 and 10

D) a solution with a pH greater than 7 that is not a buffer solution

(E) a solution with a pH of 7

Ionization Constants

CH3COOH = 1.8 × 10- 5 NH3 = 1.8 × 10-5 H2CO3; K1= 4 ×10-7 H2CO3; K2 = 4 × 10-11 8.

8.A solution prepared to be initially 1 M in NaCl and 1 M in HCl.

9. A solution prepared to be initially 1 M in Na2CO3 and 1 M in CH3COONa

10. A solution prepared to be initially 0.5 M in CH3COOH and 1 M in CH3COONa

Answers: A,D,B

50.0 mL of 0.100 M H₂SO₃ is titrated with 0.150 M KOH soluion.

a) What is the initial pH of the sulfurous acid?

b) How much titrant is needed to reach the equivalence points? What is the pH at each equivalence point?

c) What is the pH of the solution after the following points of the titration (with 0.150 M KOH)? (20.0 mL, 33.3 mL, 60.0 mL, 70.0 mL, 100.0 mL, 120.0 mL, 130.0 mL)?

In 30% ethanol, a 440 bp closed circular A-form DNA is in a relaxed form (no supercoil). What are the Lk, Tw and Wr values? (Please elaborate)

By transferring the above DNA from 30% ethanol solution to water solution, the structure of this DNA molecule converts from A-form to B-form helix (10 bp/turn) without breaking its backbone. What would the Lk, Tw and Wr be? (Please elaborate)

determine the symmetry types for all vibrational modes of square-planar molecules and whether the mode would be IR active or Raman active or neither. show the drawings. HINT the symmetries of vibrational modes should be analogous to the symmetries of SALCs.

An enzyme was found that catalyzes the reaction between students, S and academic success, P (for pass); the enzyme was called studyase.

An enzyme assay was run on studyase. 10μg of studyase (molecular weight 20,000D) was placed in a set of test tubes each of which contained 1mL of the substrate student at varying concentrations and the amount of product, academic success (P) was determined.

The following results were determined:

Note 1mM = 1millimole/L = 1μmol/mL

Plot a Lineweaver-Burk plot of 1/V versus 1/S

Determine Vmax and Km for the enzyme studyase.

Calculate Kcat and the catalytic constant (kcat/km) for the enzyme. (find [E]_T as total μmoles/mL)

Another enzyme called partyase was analyzed and when 0.010 μmoles of this enzyme was assayed it was found to have a Vmax of about 50 μmol/mL/sec and a Km of 5 mM. Calculate Kcat and the catalytic constant for this enzyme.

i.Compare the 2 enzymes on the basis of affinity for the binding site and kinetic efficiency.

Consider the titration of a 23.0 −mL sample of 0.170 M CH3NH2 with 0.155 M HBr. Determine each of the following.

C) the pH at 6.0 mL of added acid. Express your answer using two decimal places.

D) the pH at one-half of the equivalence point. Express your answer using two decimal places.

E) the pH at the equivalence point .Express your answer using two decimal places.

F) the pH after adding 5.0 mL of acid beyond the equivalence point. Express your answer using two decimal places.

Using the aqueous equilibrium constants, calculate the concentration of OH- in M and pH for the following solutions (given that all are at 25 degrees celsius):

0.15 M NaBrO

8.2×10⁻² M NaHS.

A mixture that is 0.13 M in NaNO2 and 0.25 M in Ca(NO2)2.

Thank you! :)

NH3 is a weak base (Kb = 1.8 × 10–5) and so the salt NH4Cl acts as a weak acid. What is the pH of a solution that is 0.034 M in NH4Cl at 25 °C?

1.Calculate the pH of a 0.075 M soultion of hydrazoic acid, which is a weak acid. Hydrazoic acid, HN3, has an acid dissociation constant Ka, equal to 1.9 x 10-5. Also, calculate the concentrations of the azide ion (N3-) and the hydroxide ion.

2. Calculate the pH that would result if 15.0 mL of 0.075 M NaOH, strong base, were added to 15.0mL of the solution in the problem above.

I have already completed 1, just need help with 2. If you can also show your work I would greatly appreciate it. Please and thank you.

As of the writing of this text, EPA standards limit atmospheric ozone levels in urban environments to 84 ppb. How many moles of ozone would there be in the air above Los Angeles County (area about 4000 square miles; consider a height of 100 m above the ground) if ozone was at this concentration?

1) a) Calculate the pH of a buffer that is 0.12 M in lactic acid and 0.11 M in sodium lactate. (b) Calculate the pH of a buffer formed by mixing 85 mL of 0.13 M lactic acid with 95 mL of 0.15M sodium lactate.

2) You are asked to prepare a pH=3.00 buffer solution starting from 1.25 L of a 1.00 M solution of hydroflouric acid (HF) and any amount you need of sodium flouride (NaF). (a) What is the pH of the hydroflouric acid solution prior to adding sodium flouride? (b) How many grams of sodium benzoate should be added to prepare the buffer? Neglect the small volume change that occurs when the sodium benzoate is added.

3) Calculate the solubility of Mn (OH)2 in grams per liter when buffered at pH (a) 7.0, (b) 9.5, (c) 11.8

Physical Chemistry

Estimate the bubble point and dew point temperatures of a 25 mol % n-pentane, 45 mol % n-hexane, and 30 mol % n-heptane mixture at 1.013 bar.

Data:

lnP₅^vap = 10.422 - 26,799 / RT δ₅ = 7.02 (Cal/cc)^(1/2)

lnP₆^vap = 10.456 - 29,676 / RT δ₆ = 7.27 (Cal/cc)^(1/2)

lnP^vap₇ = 11.431 - 35,200 / RT δ₇ = 7.43 (Cal/cc)^(1/2)

For P in bar, T in K, and R = 8.314 J/(mol * K); The subscripts 5,6,7 designate pentane, hexane, and heptane, respectfully