Calculate the molar solubility of Ag₂CrO₄(s) in (Solubility Product K_sp at 25 °C is 9.0 × 10⁻¹²)

A) pure water

B) in 0.500 L of a solution containing 0.950 g K₂CrO₄

Hippuric acid (HC9H8NO3), found in horse urine, has pKa=3.62.

Calculate the pH in 0.150 M hippuric acid.

I need to know the procedures of the experiment below :

Separation of a Three-Component Mixture by Extraction ​

benzoic acid     ethyl 4-hydroxybenzoate diphenyl sulfone

A 1.5-gram sample of a 1:1:1 (by weight) mixture of benzoic acid, ethyl 4-hydroxybenzoate and diphenyl sulfone was added to a 125 mL separatory funnel. Isopropyl acetate (20 mL) was added to the separatory funnel and the mixture swirled until all solids had dissolved. The solution was sequentially extracted with saturated aqueous NaHCO3 solution (4 X 5 mL), then with water (1 X 5 mL); with the aqueous extracts from each extraction being added to a 50 mL beaker (beaker 1). [The separatory funnel should be shaken for at least 1 minute during each of the four NaHCO3 extractions. Venting of the funnel should be done every 20-25 seconds during each extraction. When draining off the aqueous layer in these and all subsequent extractions leave a two mm tall layer of aqueous solution in the separatory funnel. This greatly reduces the amount of organic layer that contaminates the aqueous extracts.] Next the organic layer was extracted sequentially with 5% aqueous NaOH solution (3 X 5 mL) then with water (1 X 5 mL). Each aqueous extract was collected in a 50 mL beaker (beaker 2). [The separatory funnel should be shaken for at least 1.0 minute during each NaOH extraction..] The remaining organic layer is extracted with saturated aqueous NaCl solution (5 mL) and the aqueous layer is discarded [Do not leave any water in the funnel after this extraction]. The organic layer is transferred to a 50 mL erlenmeyer flask (flask 3). The separatory funnel is washed with isopropyl acetate (2 X 2 mL) with each washing being added to flask 3. The organic solution in flask 3 is dried (Na2SO4) then decanted into a tared 50 mL Erlenmeyer flask (flask 4). The drying agent is washed with isopropyl acetate (2 X 1 mL) with each rinse being added to flask 4. The solvent in flask 4 is evaporated to give crude diphenyl sulfone as a white solid: .416 g, 83.2%, M. pt.=121-127oC. [Evaporate the solvent using a hot plate sat on a moderate (4) setting. You must be very careful not to overheat the product when all the solvent has boiled away. The only way to actually know when all of the solvent has been removed is to weight the flask at the point of “ presumed dryness”, then reheat for a few seconds and re-weigh the flask. If the weight does not change, the product is solvent free. An alternative, and probably better, procedure is to evaporate the isopropyl acetate until only 3-5 mL of solution remains, cool, add hexane (10 mL), chill in an ice bath then filter. Both procedures work well. If insufficient time remains to isolate this material on day 1, then store the dried isopropyl acetate solution in your drawer until the next lab period. The solvent will have evaporated by then. Optional: tlc (alumina,

70/30 hexane/ethyl acetate) showed a single spot, Rf = .58. The crude product is recrystallized from toluene to give the crude product; M. pt.= 125-127 C.]

The aqueous solution in beaker 1 was acidified (acid to litmus paper) by the addition of 6 M HCl solution to give a white precipitate. [Caution! Foaming will occur due to liberation of CO2] After cooling the resulting mixture in an ice bath for 10 minutes, the solid was isolated by vacuum filtration, washed with ice water (3 X 1ml), and air dried to give crude benzoic acid as a white solid: .358 g, 71.6%, M. pt.= 115-120oC. [OPTIONAL: tlc (alumina, 70/30 hexane/ethyl acetate) showed a single spot (Rf = .03). This material was recrystallized from water to give pure benzoic acid; M. pt. = 118- 120C.]

The aqueous solution in beaker 2 was acidified (acid to litmus paper) by the addition of 6 M HCl to give a white precipitate. The resulting aqueous mixture was cooled in an ice bath for 10 minutes. The resulting white solid was isolated by vacuum filtration, washed with ice water (3 X 1 mL), and air dried to give the crude ethyl 4-hydroxybenzoae: .353 g, 70.6%, M.pt.= 113-117oC. [Optional: tlc (alumina, 70/30 hexane/ethyl acetate) showed a single spot (Rf = .42). The crude material was recrystallized from 1/1 toluene/hexane to give the pure ethyl 4-hydroxybenzoate as a white solid; M. pt.= 115- 117C.]

How can the process of "aging" explain the difference between organophosphates used as pesticides and those used as chemical warfare agents?

4. The rate with which enzymes can transform a substrate varies from enzyme to enzyme, and sometimes substrate to substrate. a) How are competitive and uncompetitive reversible inhibition similar? How is their effect on rate different? b) Enzyme reaction rates drop off dramatically as temperatures pass 50 °C or so, and do not return to their previous rate when cooled. Explain the drop off in activity and the lack of return to the previously higher reaction rates after heating. c) Pepsin is an enzyme that participates in digestion in the stomach, whereas trypsin is an enzyme that participates in digestion in the small inestines. Pepsin has the highest turnover number at around pH 2, whereas trypsin has the highest turnover number around pH 8. Explain this difference.

Codeine (C18H12NO3) is a weak base, (pKb= 5.79). A solution of 5*10^-2M solution has a pH of 10. Calculate the [C18H22NO3], [C18H21NO3] and [OH-] at equilibruim.

Benzoic acid is a weak monoprotic acid occurring in most of berries. The acid dissociation constant of benzoic acid is 6.3 x 10-5. Find pH and percent of dissociation of 0.001 M solution of benzoic acid.

You want to convert 2-chloropentane(an alky halide) into 1-pentene (an alkene). Which of the following reagents would you choose? (A)NaOH/water (B)KOH/methanol

   (C)CH₃ONa/CH₃OH (D) (CH₃)₃COK/(CH₃)₃COH

1. Consider the S_N2 reaction of butyl bromide with hydroxide ion , Assuming no other changes, what effect on the reaction rate would result from simultaneously doubling the concentrations of both butyl bromide and hydroxyl ion  A. No effect (B)It would double the rate (C)it would increase the rate six times

(D) It would increase the rate four times.

5. Select the rate law for a second order reaction: (A) rate = k[RX] (B) rate = k[RX]²[OH^-]

(C) rate = k[RX][OH^-] (D) rate k[RX]²[OH^-]²

Describe the extraction of magnesium from seawater in the Dow process. Show all relevant equations involved in the process, starting with the precipitation of Mg2+ as Mg(OH)2(s) using CaO(s) until the electrolysis of molten MgCl2.

The data below was collected in an experiment to determine the solubility of sodium nitrate at 20 Celsius degree.

1. If 5.0000g of NaNO3 was used, calculate the solubility in units of g NaNO3/100g water at each saturation temperature. Show your first calculation. Complete the rest of the calculations and fill in the table.

2. Construct a graph of solubility as a function of saturation.

3. Determine the solubility of sodium nitrate at 20 Celsius degree from a graph.

4. Using the solubility from #3, calculate the percent by mass of the salt in a saturated solution at 20 Celsius degree.

5. If the density of a saturated solution of sodium nitrate at 20 Celsius degree is found to be 1.4g/mL, calculate the Molarity of the solution.

For each pair of elements and compounds listed below, discuss their similarities and/or differences in terms of physical and chemical properties.

(a) Boron (B) and silicon (Si)

(b) BeCl2 and MgCl2;

(c) Al2O3 and In2O3;

What is the pH of a 0.39 M solution of sodium oxalate, Na₂C₂O₄? Acid ionization constants for oxalic acid are K_a1 = 5.6 x 10^-2 and K_a2= 5.4 x 10^-5.

Draw the mechanism and label products and reactants for the synthesis of aniline to 4-Bromo-2-Chloroacetanilide:

Aniline + Acetic Anhydride --> Acetanilide + Acetic Acid

Acetanilide + Bromine --> 4-Bromoacetanilide

STEP 1: Hydrochloric Acid + Sodium Chlorate --> Chlorine + Water + Sodium Chloride

STEP 2: 4-Bromoacetanilide + Chlorine --> 4-Bromo-2-Chloroacetanilide

4-Bromo-2-Chloroacetanilide + Ethanol --> 4-Bromo-2-Chloroaniline + Ethyl Acetate

Show all lone pairs or formal charges.