A student calculated the percent by mass of water in a sample of BaC12.2H20 to
be 16.4%, but the accepted value is 14.8%.
What was the student's percent error?

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

it would only be the stuff in module eight so you need to study all the lessons in that you also could check the flvs

hope this : )