Chemistry, 19.07.2019 03:20 shyah90

Asubstance changes state from solid to liquid. what has happened? a physical change a chemical change a chemical reaction the creation of matter

Answers: 2

Show answers

Another question on Chemistry

Chemistry, 22.06.2019 05:30

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.

Answers: 1

Answer

Chemistry, 22.06.2019 19:00

How does a catalyst increase the speed of a reaction? a. the catalyst eliminates the activated complex stage, allowing products to form immediately. b. the catalyst lowers the energy level of the reactants, making it easier for them to react. c. the catalyst makes it easier for the activated complex to form, lowering the activation energy. d. the catalyst raises the energy level of the products, making the reaction finish sooner. reset next

Answers: 1

Answer

Chemistry, 22.06.2019 22:30

Essay-alternative energy sources research sources of energy that are being developed. write a report of 350-400 words discussing the information you learned concerning the development of various energy sources and the impact that you think they will have on your life. include sources cited at the end of your report using the mla format. follow the rubric guidelines. note that wikipedia is not an appropriate resource for a research paper. worth 99

Answers: 3

Answer

Chemistry, 23.06.2019 01:30

List and describe the neurological effects of the vocs and other air pollutants,as described by dr.theo colborn

Answers: 2

Answer

You know the right answer?

Asubstance changes state from solid to liquid. what has happened? a physical change a chemical chan...

Questions