Consider the free radical polymerization of styrene (MW of 104) in the solvent toluene (MW of 92) at 60oC. The initiator is di-t-butyl peroxide. The initial concentration of initiator is 0.04 mole/dm3 and can be assumed constant. The initial monomer concentration is 2 mole/dm3. The initial rates measured for initiation and propagation are ri = 1.6 x 10-9 mole/dm3-s and rp = 6.4 x 10-6 mole/dm3-s. All terminations are by disproportionation. (a) Determine the initial degree of polymerization, x!, assuming that any chain transfer is negligible. (b) In reality, there is chain transfer to styrene and the chain transfer coefficient is equal to 0.85 x 10-4. How much does transfer to styrene affect the molecular weight? (c) The ! of this polymer is too high. It should be 40,000 g/mole. One way to reduce it further is to add the chain transfer agent, CCl4, which has a CT of 9 x 10-3. How much should be added? (d) What is the monomer conversion after 10 hours? Remember that [I]0 can be assumed constant.

The earth's moon is unusually large. two popular theories of the moon's origin include the "sister world" hypothesis, which states that the moon formed from the same materials as the earth, near enough to the earth that they fell into orbit around each other. a second theory is the "capture" hypothesis, in which the moon formed elsewhere in the solar system, and the earth's gravity pulled it into its orbit. studies of what the moon is made of indicate that some of its materials had to come from the earth or from the same area of the solar system where the earth had formed. at the same time, the moon does not contain much of the material that makes up the earth's core, so the moon could not have formed from the same materials as the earth. how do the two facts above affect the described theories of the moon's origin? a. they show that scientists will never agree on where the moon came from. b. they show that more experiments on moon formation need to be done. c. they show that no theory accounts for the existence of the moon. d. they show that neither theory is complete and entirely correct.

A100-watt light bulb radiates energy at a rate of 100 j/s. (the watt, a unit of power or energy over time, is defined as 1 j/s.) if all of the light emitted has a wavelength of 525 nm , how many photons are emitted per second?

What diagram shows the ionic compound of magnesium oxide