Chemistry, 01.08.2019 02:50 natalie407888
If the half-life of carbon is about 5,730 years, then a fossil that has one-sixteenth the normal proportion of carbon-14 to carbon-12 should be about how many years old?
Answers: 1
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
Chemistry, 23.06.2019 07:20
Which of the following are acids or bases? 1. sodium hydrogen 2. barium hydroxide solution 3. carbonate solution
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Chemistry, 23.06.2019 17:20
1. list the number of drops of titrant needed to produce a color change for sample a and sample b. list the actual volume of titrant needed to produce a color change for sample a and sample b.
Answers: 1
Chemistry, 23.06.2019 19:30
(04.03 lc) which of the following is released during cellular respiration? select one: a. carbon dioxide b. glucose c. mitochondria d. oxygen
Answers: 2
If the half-life of carbon is about 5,730 years, then a fossil that has one-sixteenth the normal pro...
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