1) An unknown compound is found to burn in oxygen. When bromine is added to this unknown, the solution remains orange. What can be said about the unknown compound?

2)When a purple solution of KMnO4 is added to a different unknown, a brown precipitate forms. What can be said about this unknown?

Why is pyridine a good nucleophile for cleaving borane protecting groups from phosphanes?

3. Determine the pH (to two decimal places) of the solution that is produced by mixing 5.05 mL of 7.91×10^-5 M HI with 7.73 mL of 8.38×10^-5 M Mg(OH)₂.

Apparently a shark can smell blood up to a quarter of a mile away. How does smell travel in water? It would seem strange that if you drop ink in water it takes ages to dissipate so how can the individual particles of a smell travel so far and apparently so fast?

Explain the basis for the stacking gel portion of a polyacrylamide gel. Describe how it works with respect to the loaded protein samples as well as the running buffer components.

29. How propyl amine can be synthesized by Gabriel Synthesis? Write the mechanism of the reaction.

30. How reductive amination methodology can be applied for the synthesis of the potent CNS drug “Amphetamine”?

31. Write note on “Sandmeyer reaction”. Write down the mechanism of formation of p-Bromotoluene from pMethylaniline.

Al₂(CO₃)₃ (s) è Al₂O₃ (s) + 3 CO₂ (g)           ∆H = +579 kJ            

a. What kind of chemical reaction is taking place? Is it endo- or exothermic? Explain how you know both answers.

b. Predict the change in enthalpy for each of the following reactions:

          1. 5 Al₂(CO₃)₃ (s) è 5 Al₂O₃ (s) + 15 CO₂ (g)           ∆H = ??

          2. 3 Al₂O₃ (s) + 9 CO₂ (g) è 3 Al₂(CO₃)₃ (s)             ∆H = ??

          3. Write the balanced thermochemical equation that will have ∆H = -2316 kJ

c. How much heat is required to react 5.00 grams of the aluminum carbonate?

d. If 5250 kJ of heat is added to aluminum carbonate, how many grams of aluminum oxide will be produced?

e. Using the enthalpies of formation found in the appendix of your textbook and the thermochemical equation above, calculate the enthalpy of formation of solid aluminum carbonate

Propane gas is used as a propellant in aerosol cans.

a. Suppose a 455 mL container contains propane gas at a pressure of 1.75 atm at 25.0 ^oC. How many grams of propane are in the container?

b. If the can in part a is cooled to 5.0 ^oC and an additional 10.0 grams of propane is added to the can, what is the pressure of the propane gas? How does this pressure compare to the original pressure in part a? Whose law(s) explains this change and use the postulates of Kinetic Molecular Theory to explain the change.

c. If all the propane in the original can (as described in part a) were transferred to a balloon at STP, what volume would the propane occupy? How does this compare the original conditions in part a? Explain in terms of Kinetic Molecular Theory and gas laws.

d. The can in part a says that it can handle a pressure of 5.00 atm without bursting. What is the maximum mass of propane the can is able to hold before bursting? Whose law describes the relationship and explain the change using Kinetic Molecular Theory.

e. The can in part a says that it can handle a pressure of 5.00 atm. What is the maximum temperature to which the propane can be heated to without bursting.

a) The complete combustion of 10.0 g of solid naphthalene requires what volume of oxygen gas at 20.0 ^oC and 1.00 atm? How much heat energy will be transferred in this trial? Specify direction of heat transfer in your answer.

b) If the water vapor and carbon dioxide gas produced in the trial described in part d. is collected in a 20.0 L container at 427 ^oC and this container can only withstand a maximum of 5.00 atm of pressure, will the container stay intact or explode

C₁₀H₈ (s) + O₂ (g)   è CO₂ (g) + H₂O (g)    

In terms of entropy and the real world, what is the end result of a spontaneous process?

Part A

A 50.0-mL volume of 0.15 M HBr is titrated with 0.25 M KOH. Calculate the pH after the addition of 18.0 mL of KOH.

Part B

A 75.0-mL volume of 0.200 M NH3 (Kb=1.8×10−5) is titrated with 0.500 M HNO3. Calculate the pH after the addition of 13.0 mL of HNO3.

Part A

A 52.0-mL volume of 0.35 M CH3COOH (Ka=1.8×10−5) is titrated with 0.40 M NaOH. Calculate the pH after the addition of 25.0 mL of NaOH.

Define an acid, base, and salt as they apply to chemistry and State three examples each of acids, bases, and salts commonly used in therapeutic processes.

From the examples you state, select one acid, one base, and one salt and describe specifically how and where they are used in therapeutic processes

research on buffered aspirin. On the basis of your research, respond to the following: Define a buffer and explain how a buffer works. Analyze and explain the buffer system in buffered aspirin (carboxylic acid).

Calculate the volume of each gas sample at STP.

Part A 51.1 g He Part B 47.0 g Xe Part C 49.6 mg Cl2 Part D 3.82 kg SO2.

What is the change in enthalpy (in kJ) under standard conditions when 233.71 g of sodium sulfate dissolves in water?