A 20.00 mL Ba(OH)_2 solution of unknown concentration was neutralized by the addition of 47.67 mL of a 0.1236 M HCl solution. Write the balanced molecular equation for the neutralization reaction between HCl and Ba(OH)_2 in aqueous solution. Include physical states. 2HCl(aq) + Ba(OH)_2(aq) rightarrow BaCl_2(aq) + 2H_2O(l) Calculate the concentration of Ba(OH)_2 in the original 20.00 mL solution Calculate the concentrations of Ba^2+ and Cl^- in solution following the neutralization reaction.

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.

What are scientists who study fossils called? ( a ) astronomers. ( b ) biologists. ( c ) geologists. ( d ) paleontologists.

Achemist has dissolved a certain substance in water. the chemist knows that more of the substance could be dissolved into the water before it stops dissolving. therefore