Homework Help for Chemistry

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3- A compound insoluble in water, sodium hydroxide, and hydrochloric acid but soluble in concentrated sulfuric acid and containing nitrogen melted at 68°C. When treated with tin and hydrochloric acid, it yielded a substance that reacted with benzenesulfonyl chloride to give an alkali- soluble derivative. When the original compound was treated with zinc and hot sodium hydroxide solution, it was converted to a new substance melting at 130°C.

The product of the reaction with tin and hydrochloric acid was neutralized with base and then distilled. This distillate (in ) gave rise to the following IH NMR (60 MHz) spectrum: 5 3.32, 2H, s; 5 6.44, 2H, m; 5 6.6, 1H, m; 5 7.0, 2H, m.

4- A brown liquid (1) boiled at 193-195°C. It contained nitrogen but gave negative tests for sulfur and the halogens. It was insoluble in water but soluble in dilute acid. It did not react with acetyl chloride or benzenesulfonyl chloride. Treatment of a hydrochloric acid solution of the unknown compound with sodium nitrite, followed by neutralization, gave a compound (II) that melted at 164°C. Compound II was insoluble in alkalies but dissolved in boiling concentrated sodium hydroxide solution, with the liberation of a gas (III). This gas (III) was absorbed in water, and the aqueous solution was treated with phenyl isothiocyanate to form a compound (IV) with a melting point of 134-135°C. Careful acidification of the alkaline solution, followed by extraction, gave a compound (V) that melted at 125-126°C.

The 'H NMR spectrum of compound V(60 MHz, acetone) showed 1) 6.63, 2H, d; 1) 7.67, 2H, d; 1) 8.7, 1H, bs. The 1) 8.7 Signal was so broad as to be

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1- A liquid had a boiling point of 260°C. The compound was insoluble in water, 5% sodium hydroxide solution, and 5% hydrochloric acid solution but soluble in 96% sulfuric acid solution. The compound gave off a gas with acetyl chloride and yielded a yellow liquid with 2,4- dinitrophenylhydrazine. The compound produced an orange color with hydroiodic acid. A 4- nitrobenzoate derivative was produced from the compound with a melting point of 95°C.

2-

I. (1) White crystals, mp 117-118°C.

(2) Elemental analysis for X, N, S-negative. (X = halogen)

(3) Solubility-water (+).

(4) Classification tests:

- negative 

- positive 

- positive 

- positive 

, in -negative

Neutralization equivalent = 151 1

(5) Derivative: p-Nitrobenzyl ester, mp 123°C.

(6) Spectra: IR (mineral oil mull): 3333--2400 (s, b); 1706 (s);

1449, 1379,

1300, 1200, 1190, 943, 865, 730 cm -1 (all m). 'H NMR (60 HMz, acetone): 8 5.22, 1H, s; 8 6.93--7.88, 7H, m. 

Please show me the shape of a 4fxyz orbital but as a projection along the xy plane.

Include the radial and angular nodes as well along the xy plane

5. Which peptides would be released from the following peptide by treatment with trypsin?

    Ala-Ser-Thr-Lys-Gly-Arg-Ser-Gly (Use the three-letter code for your answer.)

13. Sodium metal can be obtained by the electrolysis of molten sodium chloride.

a. Explain why solid sodium chloride does not conduct electricity but molten sodium chloride does.

b. State the name of the product at the anode in this process and write half-equations for the reactions at each electrode, stating clearly which is which. [2] [3]

Volatile substances have lower boiling points and evaporate quickly. Rubbing alcohol is an example of this. If you sample contained a volatile impurity would you expect your calculations for the % of water in the hydrate to be too high or possibly too low? Explain.

What are the effect of inert gases in the atmosphere to the spectral emissions of hydrogen, oxygen and mercury?

3. We use models every day in our lives. For example, the temperature scale, weather forecasting, speed limits, etc. Please identify a model that you use in your everyday life and then describe how you use the model (what decisions do you make based on the information derived from the model). Finally, describe how you think the model was developed and why you or those around you use it consistently.

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7. A peptide has the sequence Glu-His-Trp-Ser-Gly-Leu-Arg-Pro-Gly.

    a) What is the one-letter designation for this polypeptide? __________

    b) Draw the chemical structure of this polypeptide at physiological pH, You may omit stereochemistry.

    c) What is the net charge of this polypeptide at pH 3, 8, and 11. 

a. At what temperature (in K) will 3.5 moles of gas occupy 2.7 L at 1.5 atm?

b. What is the volume of a container that contains 24.0 grams of N2 gas at 328K and .884 atm?

c. How many moles of O2 gas are in a 3700 mL container at a pressure of 1.3 at 330C?

a. A bike tire at a pressure of 2.4 atm and a temperature of 290K has a volume of 2.2 liters. A child gets on the bike and rides it outside. What is the new pressure if the temperature outside is 296k and his weight causes the tire's volume to drop to 2.0 liters?

b. How many moles of a gas are in a 2.2 liter balloon at 1.3 atm and 850C?

a. To what Kelvin temperature must a balloon be cooled if its original temperature was 3230C to cause a 2.85 L balloon shrink to 1.25L ?

b. What was the original volume of a gas if heating it from 22k to 85k produced a volume of 3.8 liters?

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(5pts) Part II - Volume of Regular-Shaped Solid

Calculate the volume of the regularly-shaped solid

Shape of solid                                    cylinder

Mass of solid:                                    37.300 g

Diameter of solid                                2.800 cm

Height of solid                                    3.020 cm

Measurement not needed:                   3.290 cm

(3pts) Volume of the regularly-shaped solid cylinder ()                      ____________

(2pts) Density of regularly-shaped solid (g/ml)                                       ____________

It's a multi step question that covers many sections of different chapters. I'm having trouble believing that the answers I arrived too are incorrect. Please solve each part thoroughly with explanations. Also, please do not submit incorrect work that will not help me fix any errors that I may have made. Look forward to growing.

a. What is the new pressure acting on a 2.5L balloon if its original volume was 5.8L at 3.7 atm of pressure?

b. What was the original pressure in a rigid container if the new pressure is 82.5 atm and the temperature was raised from 44 degrees Celcius to 67 degrees Celcius?