Q#1. Draw a simple schematic of the electron energy levels for:
a) an atom of H and a dimer (2 atoms) of H
b) an atom of Li, a dimer of Li, and a solid of Li. To what extent
the valence band is filled in solid Li?
Label each energy level/band (ie, 1s, 2s, etc.)

Reading:Materials Science and Engineering,An Introduction by William D.Callisler Ch. 18

a 2.00 l container holds 4.00 moles of o2 and 2.70 moles of he at 293 k. What is the partial pressure of o2? He? what is the total pressure?

“When a strong base is gradually added dropwise to a weak acid, the pH changes at each addition. When the appropriate quantity of base has been added to react with all of the acid, the pH changes sharply, indicating the endpoint of the titration. A plot of pH versus volume of base added gives what is known as a titration curve”.

Consider the titration of 25.00 mL of 0.1000 M benzoic acid with 0.1000 M NaOH,.

Write a balanced chemical equation for the titration reaction using C6H5COOH for benzoic acid’s formula.

Determine the volume of NaOH solution required to reach the endpoint.

The chart on the next page has entries for several steps along the titration curve. To calculate the pH at each step, you first must understand the chemistry at that step, and then you can decide the appropriate method to calculate the pH. For each volume listed, (i) list the major species in solution, (ii) determine whether the Ka equation, Kb equation, buffer equation, or solution equilibrium equation is appropriate for the calculation of the solution [H3O+] and pH, and (iii) complete the calculations.

- 25.0-L tank contains 295 g N₂, 135 g O₂, and 24.0 He gases. Calculate the partial pressure of each gas and the total gas pressure at 20.0^oC.

         (Answer: P_N2 = 10.1 atm; P_O2 = 4.06 atm; P_He = 5.77 atm; P_total = 19.9 atm)

- A 5.0-gallon gas tank contains N₂ and H₂ gas, such that the partial pressure of H₂ is three times that of N₂ gas. If the total gas pressure is 2.4 atm at 25^oC, how many grams of N₂ and H₂, respectively, are present? (Answer: 13 g of N₂ and 2.8 g of H₂)

Thank you for your your help, if you can help me showing me the process to learn about it at least of one I will appreciate

1. Calculate the moles of product produced in the ractions, if 4.00g of the hydrate was used in the reaction

FeCl₂ * 4H₂O_(aq) + H₂C₂O_4(aq) -> FeC₂O₄ * 2H₂O_(s) +2H₂O_(I) + 2HCl_(aq)

Ni(NO₂)₂ * 6H₂O_(aq) +H₂C₂O_4(aq) -> NiC₂O₄ * 2H₂O_(s) + 4H₂O_(I) + 2HNO_3(aq)

MnSO₄ * H₂O_(aq) + H₂C₂O_4(aq) + 2H₂O_(I) -> MnC₂O₄ * 3H₂O_(s) + 3H₂O_(I) + H₂SO_4(aq)

a statement of the first law of thermodynamics is that a. in a spontaneous process, the entropy of the universe increases b. there is no disorder in a perfect crystal at 0 k. c. the total energy of the universe is constant. d. the totla energy of the universe is constant. e. mass and energy are conserved in all chemical reactions

A voltaic cell employs the following redox reaction: 2Fe3+(aq)+3Mg(s)→2Fe(s)+3Mg2+(aq) Calculate the cell potential at 25 ∘C under each of the following conditions.

Part A standard conditions

Part B [Fe³⁺]=1.9×10⁻³ M ; [Mg²⁺]=1.80 M

Part C [Fe³⁺]=1.80 M ; [Mg²⁺]=1.9×10⁻³ M

1. How many grams of helium must be released to reduce the pressure to 69 atm assuming ideal gas behavior?

2. If the pressure exerted by ozone, O3, in the stratosphere is 3.0×10−3atm and the temperature is 251 K , how many ozone molecules are in a liter?

3. Carbon dioxide makes up approximately 0.04% of Earth's atmosphere. If you collect a 3.0 L sample from the atmosphere at sea level (1.00 atm) on a warm day (29 ∘C), how many CO2 molecules are in your sample?

Using tabulated Ka and Kb values, calculate the pH of the following solutions.

Answer to 2 decimal places.

A solution containing 1.9×10-1 M HNO2 and 2.4×10-1 M NaNO2.

A solution made by mixing 110.00 mL of 1.100 M CH₃COOH with 35.00 mL of 0.750 M NaOH.

This is the second time I'm posting this question so I hope someone can explain it clearly.

A mixture of benzene and toluene is in a tank whose pressure is maintained at 2.0 atm. Observation through a sight glass on the vessel shows that half of the tank volume is occupied by liquid. Analysis shows that the liquid contains 50.0 wt% benzene and the balance toluene. Raoult's law applies at all composition s, and the density of the liquid is essentially independent of temperature. Estimate (a) the temperature and (b) the fraction of the system mass in the liquid phase

A municipal water treatment plant is designed to produce 20 million gallons per day (MGD) of potable water. The plant treats surface water using coagulation followed by sedimentation, filtration, and chlorination. Although the water is hard, it is not presently softened. The water is coagulated using a 30 mg/L dosage of alum (aluminum sulfate, Al2(SO4)3•14.3H2O, MW = 600). This chemical reacts in water to form Al(OH)3 as follows:

Al2(SO4)3 + 6HCO3- → 2Al(OH)3(s) + 3SO4-2 + 6CO2

How many mg/L of bicarbonate (alkalinity) will be "consumed" (converted to CO2) when the

alumisadded? (AWs: Al=27,S=32,C=12,0=16,H=1,Ca=40)

Estimate the pH of the water following coagulant addition. Assume an initial bicarbonate concentration of 244 mg/L and water initially in equilibrium with the atmosphere (i.e., H2CO3* = 10-5 M). (Hints: assume negligible loss of CO2 to the atmosphere from the deep basins used for treatment; adjust the concentrations of HCO3- and H2CO3*, based on your answer to Problem 1; then use the expression for K1 to solve for [H+] following coagulant addition. Assume [OH-] and [CO3-2] are negligible.)

How many mg/L of hydrated lime, Ca(OH)2, would be needed to keep the pH constant when the alum is added? Hint: the neutralization reaction can be represented as follows:

Al2(SO4)3 + 3Ca(OH)2 → 2Al(OH)3 + 3Ca+2 + 3SO4-2

You are asked to run a chromatographic column for separation of a mixture of compounds: CH3CH2OCH3, CH3(CH2)3OH, CH3CO2H, CH3(CH2)8CH3. Two solvents have been provided i.e. acetone and hexane. Which eluting solvent would you use first and predict the order of elution for the compounds.

Please show how work on how you got this answer.

Q1: What will be the pressure (in mmHg) inside of a 50.0 L container that holds 7.00 moles of hydrogen gas at 0.0 C?

Q2: Oxygen Gass is produced for use in a small-scale experiment by the catalytic decomposition of hydrogen peroxide:

2 H2O2 (aq) -------------------> 2 H2O (l) + O2 (g)

If 50.0 mL of a 1.00 M solution of H2O2 completely decomposes and what volume of dry oxygen gas can be collected at 21.5 C and 742 mmHg?