Select the correct answer.
given the law of conservation of energy, what happens when a 200°c iron bar is placed in thermal contact with a 30°c block of wood?
a energy leaves the iron bar and enters the wood until the temperatures are equal
b. energy leaves the wood and enters the iron bar until the temperatures are equal
c. all the energy from the iron bar is transferred to the wood,
d. all the energy from the wood is transferred to the iron bar.

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.

Δu of , in kj/kg, as it isto k, (a)as a of , (b) at , (c) at .

What volume of argon gas is equal to 1.60 grams of argon