A mixture of carbon dioxide and nitrogen gases, in a 7.69 L flask at 36 °C, contains 10.4 grams of carbon dioxide and 7.77 grams of nitrogen. The partial pressure ofnitrogen in the flask is (?) atm and the total pressure in the flask is (?) atm

thanks in advance

You have 200 ml of 0.1M HEPES buffer, pH 7.5. You add 2 ml of 0.4M HCl. The pKa of HEPES is 7.5.

a) what will the resulting pH be?

b) what would the pH be if no HEPES were present (that is, you mixed water and HCl)?

Determine the pH at the equivalence point when 0.05 M KOH is titrated with 50.0 ml of 0.01 M benzoic acid HC₇H₅O₂. The K_a for benzoic acid is 6.3 x10^-5.

Physical Chemistry problem:

How does the confinement of a particle to a finite region of space lead to the quantization of its energy? You may use any combination of words, images, or equations to support your answer.

calculate the molar solubility of of Ag2CO3 in a solution that is buffered to a phone of 7.50

Carbohydrates:

what is the difference in monosacchrides, disaccharides, and polysacchrides?

What are the structures of glucose, frustose, sucrose, lactose, and starch, such that you could predict their responses in the following tests:

Benedicts test (remains bright blue if negative for a reducing sugar, turns any other color if positive for reducing sugar. Tests for free or potentially free aldehyde or ketone groups)

Seliwanoff’s Test (turns red or pink, speed of color change indicates ketose vs. aldose, and monosacchride vs. disaccharide)

Iodine Test – tests for polysaccharides, turns blue-black in starch, red-to-brown color in other polysaccharides

A reaction was run with two different initial concentrations of reactants A and B:

What is the order of the reaction with respect to B?

A reaction was run with two different initial concentrations of reactants A and B:

What is the order of the reaction with respect to B?

Fermentation Test – if we sketch the fermentation tube, what are the expected results?

Hydrolysis of di- and polysaccharides – can disaccharides and polysaccharides undergo hydrolysis? (YES!!) How did the tests you conducted support your answer?

Thermodynamics assumes that matter is in its equilibrium state in order to make its calculations. Please, indicate whether or not the systems below may or may have not achieved an equilibrium state and explain your reason for your choice

1) A glass of water at room temperature and 1 atm held for 48 hr

2) A tray of water just placed in the icemaker section of the refrigerator

3) Corrosion of a metal in seawater

4) A closed teapot with boiling water at 212 oF and 1 atm

5) A piston-cylinder assembly containing a gas at 5 atm was suddenly released to 1 atm

please can answer all the questions and with work clearly

1. According to the Joslin Clinic, healthy individuals without diabetes should have a blood glucose level of no more than 100 mg dL−1 after awaking, before breakfast. What is the molarity of glucose in the blood of a healthy individual whose blood glucose level is 100 mg dL−1 ?

2. One index of toxicity is the LD50, the amount of substance which, when administered to a group of subject, will kill 50% of that group. (LD50 stands for lethal dose of 50%.) It is known that LD50s are different for different species; for example, for aspirin, the LD50 in cats is about 5 mg kg−1 , while in dogs, it is about 11 mg kg −1 , and in rats, it is about 200 mg kg−1 . In a recent editorial, Dr. Bernd Mayer of the University of Graz, Austria, discusses the accepted lethal dose of nicotine in humans. According to Dr. Mayer, the widely accepted value of 800 mcg kg−1 (mcg is a common abbreviation for microgram, µg, and 1 mg = 1000 mcg) is based on a casual statement in a 1906 toxicology text, and is far smaller than the values determined for laboratory animals, which are range from 3.3 (mice) to more than 50 mg/kg (rats).

(a) Assuming that the accepted value is correct, how many more times toxic is nicotine towards humans than rats?

(b) Assuming that the accepted value is incorrect and that nicotine is as toxic in humans as in rats, what is the expected lethal dose, in grams, for a 120 lb woman? For a 180 lb man?

c) Depending on brand, smoking a cigarette results in an uptake of approximately 2 mg of nicotine. How many cigarettes must be smoked by a 120 lb woman to achieve the lethal dose of nicotine? How many for the 180 lb man?

3. It is approximately 59 miles from Indiana to Pittsburgh. According to the EPA, the commercially available vehicle with the highest gas mileage is the BMW i3 BEV, which achieves 124 mpg.

(a) How many gallons of gas are required to drive to Pittsburgh and back?

(b) Assuming gasoline is 100% octane, how many moles of octane are required to drive to Pittsburgh and back?

(c) Assuming complete combustion of the fuel, how many grams of CO2 are produced by driving to Pittsburgh and back?

4. The U.S. EPA currently sets the maximum allowable concentration of lead in public drinking water at 15 µg L−1 .

(a) What is the molarity of Pb, if the concentration of Pb is 15 µg L−1

(b) If you allow one gallon of such water to evaporate to dryness, how many grams of Pb are left behind?

(c) How many gallons of such water must you drink in order to have drunk a mole of lead?

5. On the Moodle site, you will find a file, HydocarbonDensity.xls. This is an Excel file listing the names, number of carbons, molar masses, refractive indices, and densities of 35 unbranched alkanes.

(a) Make a plot of the density of unbranched alkanes versus the number of carbon atoms in the alkane.

(b) Given that commercial polyethylenes have densities between 0.91-0.96 g/mL, use your plot to estimate the number of carbon atoms in commercial polyethylene. You should explain your process in writing.

For the standardization of their sodium hydroxide solution a pair of students weighed out 0.4607 g of KHP (MM 204.22 g/mol). They found that it took 20.26 mL of their NaOH solution to reach the endpoint. What is the concentration of their NaOH solution in M?

Functional Group Identification:

What are the functional groups (alkanes, alkenes, alcohols, aldehydes, ketones, phenol)?

how is reaction with Br2: (and how this can be used to test for alkanes, alkenes with and without light)

Explain Ceric nitrate test (tests for alcohol functional group): turns red in presence of hydroxyl, turns green-brown in presence of phenol.

FeCl3 test: phenols turn red-purple

2,4-DNP (tests for aldehydes and ketones): yellow-red = carbonyl present, but it does not help you decide between the aldehyde and ketone.

Why Tollen’s Reagent: reacts with aldehydes, does not react with ketones, appears to “silver” the solution ?

Polymers:

What is the difference between monomers and polymers, basic understanding of a polymerization?

what is the synthesis and characterization of nylon, gluep, and slime?

How to use a table of types of plastics, their response to acetone, and their density to predict an unknown?

A sample containing acetaminophen was dissolved in water to make a 50.00-mL solution. The solution was titrated with 0.5065 M NaOH, and the equivalence point was reached when 26.10 mL NaOH solution was added.

The terminal hydrogen (on the OH) is removed during neutralization. The Ka value of acetaminophen is 3.2 × 10−10.

Calculate the pH at the equivalence point.

If a temperature increase from 19.0 ∘C to 37.0 ∘C triples the rate constant for a reaction, what is the value of the activation barrier for the reaction?