Enough of a monoprotic acid is dissolved in water to produce a 1.35 m solution. the ph of the resulting solution is 2.93. calculate the ka for the acid.

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.

In a heat of an engine, if 700 j enters the system, and the piston does 400 j of work what is the final internal (thermal) energy of the system if the initial energy is 1,500 j

Imagine a small synthetic vesicle made from pure phospholipids enclosing an interior lumen containing 1 mm glucose and 1 mm sodium chloride. if the vesicle is placed in pure water, which of the following happens faster? a. na+ diffuses out. b. cl– diffuses out. c. h2o diffuses in. d. glucose diffuses out. e. sodium chloride diffuses out.