In an upcoming experiment, you will carry out the Diels Alder reaction of anthracene-9-methanol

and N-methylmaleimide. To simplify the modeling, examine the reaction of anthracene with

maleimide (shown above). The goal of this exercise is to examine the dramatic changes in

molecular structure and increases in molecular complexity that accompany the Diels Alder

reaction.

Question: Can the Diels Alder adduct 1 have endo and exo isomers? Why/why not?

The top portion is for context I hope. The question has me confused. Please help.

In a test of the effectiveness of garlic for lowering​ cholesterol, 49 subjects were treated with garlic in a processed tablet form. Cholesterol levels were measured before and after the treatment. The changes ​(beforeminus​after) in their levels of LDL cholesterol​ (in mg/dL) have a mean of 2.7 and a standard deviation of 16.8. Construct a 99​% confidence interval estimate of the mean net change in LDL cholesterol after the garlic treatment. What does the confidence interval suggest about the effectiveness of garlic in reducing LDL​ cholesterol?

Starting from volume VA and pressure PA, an ideal gas undergoes the following three-stage, reversible, cyclic process: (i) adiabatic expansion to volume VB, then (ii) isochoric heating to pressure PA, then (iii) isobaric cooling to volume VA. Draw this process on a P V -diagram, and evaluate the change in the entropy of the system (∆S), for each stage. Show that the sum of these entropy changes is zero, as it should be since the system returns to its initial state. Assume CV and CP are constant.

Assuming that no equilibria other than dissolution are involved, calculate the concentration of all solute species in each of the following solutions of salts in contact with a solution containing a common ion. Show that changes in the initial concentrations of the common ions can be neglected.

(a) TlCl(s) in 1.250 M HCl

(b) PbI2(s) in 0.0355 M CaI2

(c) Ag2CrO4(s) in 0.225 L of a solution containing 0.856 g of K2CrO4

(d) Cd(OH)2(s) in a solution buffered at a pH of 10.995

The following reaction has achieved equilibrium. Predict the effect on the formation of phosphorous pentachloride (increase, decrease or no effect) for the stated changes to the system:

PCl5(g)←→PCl3(g)_Cl2(g)

A) The concentration of phosphorous trichloride is increased.

B) The concentration of chlorine is increased.

C) The volume of the container in which the reaction is taking place is suddenly made smaller.

D) The pressure of the system is increased by adding one atmosphere of gaseous nitrogen to the container.

Could you please explain your answers? Thank you!

1) Draw the structure of the product formed by addition of vitamin B₁ and benzaldehyde.

2) Ammonia adds to carbonyl groups but is ineffective as a catalyst for the benzoin condensation. Explain.

3) Write a balanced oxidation-reduction equation for the oxidation of benzoin by ammonium nitrate (the cupric ion catalysis need not to be considered).

4) In the benzil oxidation the initial blue color changes to gren as the reaction proceeds. Why?

5) In dilantin sodium it is the imide proton that is abstracted rather than the amide proton. Why?

1) Draw the structure of the product formed by addition of vitamin B₁ and benzaldehyde.

2) Ammonia adds to carbonyl groups but is ineffective as a catalyst for the benzoin condensation. Explain.

3) Write a balanced oxidation-reduction equation for the oxidation of benzoin by ammonium nitrate (the cupric ion catalysis need not to be considered).

4) In the benzil oxidation the initial blue color changes to gren as the reaction proceeds. Why?

5) In dilantin sodium it is the imide proton that is abstracted rather than the amide proton. Why?

1. Discuss the implications of the spread and change of species distributions after the retreat of the Pleistocene glaciers for evolutionary changes in species and for the species composition of ecological communities.

2. Describe the major mass extinctions over geological time. When did each occur? What was the most probable cause for each mass extinction event? What is the evidence to support each cause? How does the background rate of extinction over most of geological time compare to our current rate of extinction in present time?

Consider an electron initially moving in the positive x-direction along the negative x-axis with an energy E. At the origin the electron encounters a square barrier; the potential energy U (x) changes abruptly, from ? U(x)=0? for x<0, to U ( x) 1.0eV for 0<x<a. to U(x)=0 for x>a, where the barrier width a=1 nm . Graph the transmittance as a function of energy, for the range 0 <E<5eV . For what values of energy is there a transmission resonance?