Select all that apply. salt dissolved in water is a solution, therefore
a. salt and water are chemically combined
b. salt is not chemically bonded to water
c. the quantity of salt and water is fixed
d. the ratio of salt to water may vary
e. salt and water retain their own chemical properties

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 should have an internal chamber and two thermometers sticking out of the top. the internal chamber will also be closed off from the outside.