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Chemistry Samples

How much electricity can a turbine generate in one year?

Assume a wind turbine with a hub 50 meters above the ground, a rotor diameter of 50 meters and a wind-conversion efficiency of 25 percent. The turbine operates in an area with an average wind-power density of 500 watts/sq meter at 50 meters altitude. How much electricity (kWh) can the turbine generate per year? Wind densities greater than or equal to 500 watts/sq meter at an altitude of 50 meters are present on 1.300 percent of the land area of the US. If, on average, wind farms contain 8 turbines/sq km, how much electricity (kWh/yr) could be generated from these wind turbines? (The area of the US is 7,827,989 sq km).

Flow Rate & Pesticide Concentration

A certain pesticide is fatal to fish fingerlings at a level of 0.5 parts per million in water. A leaking metal can containing 10.0 kg of the pesticide was dumped into a stream with a flow of 10.0 Liters per second moving at 0.7 km/hr. The container leaks pesticide at a constant rate of 5.0 mg/sec. For what distance (in km) downstream is the water contaminated by fatal levels of the pesticide by the time the container is empty?

Amount of Coal Needed to Produce a pH of 2

How many metric tons of 5%-S coal would be needed to yield the H2SO4 required to produce a 5.0 cm rainfall of pH 2.00 over an area of 100 square kilometers? Hint: calculate the volume of rain, mol H+, mass of S, mass of coal. If you could work out the problem for me, that would be great! It makes it easier to understand.

Thickness of a Membrane

You have been investigating a membrane protein that appears to have seven 24 residue transmembrane Alpha helices. Assume that each helix is perpendicular to the plane of the membrane and goes exactly from side of the membrane to the other. Also assume that each helix is linked to the next by a loop with a minimun of 12 amino acid residues. A) From typical helix parameters and the information given, estimate the thickness of the membrane? B) What is the minimum number of residues in this protein? C) Using the result of B) estimate the molecular weight of this protein? D) How many mainchain H-bonds are in each helix? E) What types of amino acids residues do you expect to make up...


A friend insists that all mutagens are dangerous. How would you respond?

Non-Covalent Interactions In Proteins

Which non covalent interactions are most likely to be important in protein-protein interactions in aqueous environment? What is the driving force for proteins that are embedded in lipid membranes?