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?

Assume Raoult's Law applies to a binary mixture of water and methanol at 70 C.

a) Which species should be considered species (a)? Why?

b) Prepare a Pxy diagram for this mixture

c) What is the composition of the vapor in equilibrium with liquid at x_i for methanol of 0.3?

d) What is the composition of the liquid in equilibrium with vapor at y_i for water of 0.3?

For parts (c) and (d), determine these composition values analytically. Then confirm that they are correct on the Pxy diagram you created in part (b).

To a 100.0 mL volumetric flask were added 7.00 mL of 1.70 M of H3VO4, 1.401 g of NaH2VO4, and 15.00 mL of 1.5 M NaOH. The flask was filled to the calibration mark with water. What were the molar concentrations of H+, OH-, the two other relevant molecules and the pH of the solution? Is the resulting solution a buffer? Ka1 = 1.0 x 10-4, Ka2 = 2.8 x 10-9 and Ka3 = 5.0 x 10-15 for H3VO4.

Calculate the pH of a 0.800 M NaCH3CO2 solution. Ka for acetic acid, CH3CO2H, is 1.8 × 10-5. If someone could list the steps and calculations that would be helpful. Thank you!

Denaturation can occur if a protein is heated or undergoes changes in pH. Denaturation disrupts the secondary, tertiary, and quaternary structure of a protein. Would you expect the Biuret test to work on a protein that had been denatured? Why or why not?

(a) How many grams of CaCl2 are needed to make 798.0 g of a solution that is 32.5% (m/m) calcium chloride in water? Note that mass is not technically the same thing as weight, but (m/m) has the same meaning as (w/w).

-How many grams of water are needed to make this solution?

(b) What is the volume percent % (v/v) of an alcohol solution made by dissolving 147 mL of isopropyl alcohol in 731 mL of water? (Assume that volumes are additive.)

(c) The mass of solute per 100 mL of solution is abbreviated as % (m/v). (The abbreviation % (w/v) is also common.) How many grams of sucrose are needed to make 915 mL of a 38.0% (w/v) sucrose solution?