Identify the nervous system responsible for calming the body and conserving energy.

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.

Calculate the ph at the equivalence point for the titration of a solution containing 150.0 mg of ethylamine (c2h5nh2) with 0.1000 m hcl solution. the volume of the solution at the equivalence point is 250.0 ml. kb forethylamine is 4.7 × 10−4 .

When hydrogen peroxide (h2o2) is added to potassium iodide (ki) solution, the hydrogen peroxide decomposes into water (h2o) and oxygen (o2). the chemical equation for the decomposition reaction is: 2h2o2—> 2h2o + o2. what is the role of the potassium iodide in this reaction? a. reactant. b. product. c. precipitate. d. catalyst.