When mixing an acid with water, which of the following must always be done? A.
Never mix an acid with water, it will explode.
B.
Always add the acid to the water slowly, taking a moment to stir between drops.
C.
Always heat the acid before mixing with water.
D.
Always shake both solutions before mixing.

Achef makes salad dressing by mixing oil, vinegar, and spices, as shown. which type of matter is the salad dressing?

Atrain travels 74 kilometers in 3 hours, and then 81 kilometers in 5 hours. what is its average speed?

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.