Chemistry
Chemistry, 29.07.2019 12:30, Isaac0213

Henry mixed salt and water together in a cup until he observed a clear solution. he measured the mass of the solution. then he placed the cup outside for several sunny days during the summer. after a week, he observed that only solid salt remained in the cup and the mass had decreased. henry concluded that a physical and chemical change occurred in this investigation. which statements correctly defend or dispute his conclusion? he is correct. dissolving salt in water is a physical change, but evaporating the water is a chemical change. formation of a solid is evidence that a chemical change occurred. he is correct. evaporation is a physical change, but dissolving salt in water is a chemical change. the change in mass is evidence that a chemical change occurred. he is incorrect. dissolving salt in water and evaporation of the water are both physical changes. the reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change. he is incorrect. dissolving salt in water and evaporation of the water are both chemical changes. the reappearance of salt is evidence that the change was reversible by a chemical change, so it could not be a physical change.

answer
Answers: 2

Other questions on the subject: Chemistry

image
Chemistry, 22.06.2019 00:30, S4NCHEZ28
Sarah wants to know where in her garden chamomile would grow the best. she thinks chamomile will grow best in the corner of the garden that gets the most sunlight. to test her hypothesis, she decides to plant several groups of chamomile in her garden as an experiment. which of the following variables will sarah need to measure to know which group of plants grew best? a. the location of the plants b. the type of plants c. the height of the plants d. the amount of water she gives the plants
Answers: 1
image
Chemistry, 22.06.2019 01:10, mistiehaas
Which of the following elements would you expect to have the lowest ionization energy value? fluorine, lithium, neon, nitrogen
Answers: 2
image
Chemistry, 22.06.2019 05:30, MansellS5529
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
image
Chemistry, 22.06.2019 06:30, ajay67
Summarize possible ways in which phases of matter could combine to form a solution.
Answers: 2
Do you know the correct answer?
Henry mixed salt and water together in a cup until he observed a clear solution. he measured the mas...

Questions in other subjects: