What is the purpose of performing mixed melting point experiments? For example, if your unknown is phenacetin, what do you expect to see with a mixed melting point experiment using your unknown and phenacetin out of a bottle? What do you expect to see with a mixed melting point using your unknown and acetanilide out of a bottle?

In the photoelectric experiment, green light, with a wavelength of 522 nm is the longest-wavelength radiation that can cause the photoemission ofelectrons from a clean sodium surface.

1. a) What is the work function of sodium, in electron-volts?

2. b) If UV (ultraviolet) radiation of wavelength 250 nm is incident to the sodium surface, whatwill be the kinetic energy of the photoemitted electrons, in electron-volts?

An experiment is designed to test the potency of a drug on 10 rats. Previous animal studies have shown that a 10-mg dose of the drug is lethal 5% of the time.

1. What is the probability that exactly 0 rats will die?
2. What is the probability that 1 or more rats will die?
3. What is the mean (or the expected number of deaths) and standard deviation for this probability distribution?

1) When the percent recovery is less than 100%, where is most of the uncovered material and how might you go about recovering it if you needed to? (three of fewer sentences)

2) Hot filtration was not necessary in the recrystallization of phthalic acid but was necessary in the recrystallization of naphthalene. Why was it necessary in the recrystallization of naphthalene?

Both of these are about a recrystallization experiment.

Please no cursive

1) Draw the structure of caffeine and determine the most basic nitrogen and specifically explain your rationale with the use of Lewis structures. You may need to research this.

2) The purpose of synthesizing a caffeine derivative involves melting points. Draw the structure of the specific derivative from THIS experiment, and explain how it differs from caffeine.

In the Anfinsen protein folding experiment the sequence of removing urea or BME makes a difference for functional refolding of the protein. Explain why removing BME first leads to a nonfunctional enzyme, but removing urea first leads to a functional enzyme. Why does adding small amounts of BME alone to the solution with the nonfunctional enzyme "rescue" the function

biochemistry

An antibiotic, which is also used as an anticancer drug, was isolated from Streptomycetes bacteria. Its elemental analysis gives the following composition (by weight):

%C 57.89

%H 6.87

%N 13.97

%O 21.27

The formula weight is found (in a seperate experiment) to be NEAR 1300g/mole. Determine the MOLECULAR FORMULA of the antibiotic. show ALL work.

1.) Define standard temperature and pressure(STP). What is the value of the molar volume of any ideal gas at STP?

2.) What type of reaction is used to determine the yield of hydrogen gas in this experiment? Explain choice.

3.) How many grams of hydrogen can be expected from complete reaction of 1.0 g of Mg? Show work!

Explain why the pH scale is a convenient tool to measure the acidity or basicity of a substance.

The definition for acids and bases provided in the introduction to this experiment is called theBronsted-Lowry formulation. Another formulation, that of Arrhenius, defines an acid as a speciesthat supplies H+ to solution and a base as something that supplies OH- to solution. Whichexplanation is more inclusive than the other, and why?

23. Consider the following experiment. Pick a random integer from 1 to 10¹².

    1. (a) What is the probability that it is either a perfect square (1, 4, 9, 16, ...) or a perfect cube (1, 8, 27, 64,...)?

    2. (b) What is the probability that it is either a perfect fourth power (1, 16, 81, 256, ...) or a perfectsixth power (1, 64, 729, 4096,...)?