Stacy runs a paper chromatography experiment using the same ink, but two different solvents. using solvent a results in the ink separating into three bands, but solvent b does not carry the ink away from the original spot.
which of the following could explain the results?
a) solvent a was not a good mobile phase because it could not dissolve the ink.
b) solvent b was not a good mobile phase because it could not dissolve the ink.
c)the ink was a pure substance and dissolved in both solvents.
d) the ink was a mixture, but only in solvent a.

In a laboratory experiment, a fermenting aqueous solution of glucose and yeast produces carbon dioxide gas and ethanol. the solution was heated by burning natural gas in a bunsen burner to distill the ethanol that formed in the flask. during the distillation, the ethanol evaporated and then condensed in the receiving flask. the flame of the burner was kept too close to the bottom of the flask and some of the glucose decomposed into a black carbon deposit on the inside of the flask. during this experiment the following changes occurred. which of these changes involved a physical change and not a chemical change? check all that apply. 1-condensation of ethanol 2-evaporation of ethanol 3- formation of carbon dioxide gas from glucose burning of natural gas 4-formation of ethanol from glucose by yeast 5-formation of a carbon deposit inside the flask

Convert .347 kilometers to miles show your work

Apound is approximately 0.45 kilogram. a persons weighs 87 kilograms. what is the persons’s weight, in pounds, when expressed to the correct number of significant figures