Suppose that a piece of polystyrene insulation board has a thermal conductivity of k= 0.04 W/m⋅K. In comparison copper has a thermal conductivity of about 400 W/m⋅K. If you want to make a wall of copper that provides the same insulation as a 4-cm polystyrene board, how thick does the copper wall have to be (in meters)? ANY HELP WITH THIS WOULD BE APPRETIATED (PLEASE INCLUDE WORK IF NEEDED)

Explain why pure hydrogen cyanide does not conduct electricity, but become a conductor when it is dissolved in water? (at room temp, pure hcn exists as a volatile liquid)

A3.37-mg sample of protein was chemically digested to convert its nitrogen into ammonia and then diluted to 100.0 ml. then 10.0 ml of this solution was placed in a 50-ml volumetric flask and treated with 5 ml of phenol solution plus 2 ml of sodium hypochlorite solution. the sample was diluted to 50.0 ml, and the absorbance at 625 nm was measured in a 1.00-cm cuvette and found to be 0.486. for reference, a standard solution was prepared from 10.0 mg of nh4cl (molar mass = 53.49 grams/mole) dissolved in 1.00 l of water. then 10.0 ml of this standard was placed in a 50-ml volumetric flask, treated in the same manner as the unknown, and the absorbance found to be 0.323. finally, a reagent blank was prepared using distilled water in place of unknown, it was treated in the same manner as the unknown, and the absorbance found to be 0.076. calculate the weight percent of nitrogen in the protein.

How does the viscosity of magma change as magma cools?