What property of the following reaction might be qualitatively measured to follow the rate of reaction?

A) C(s) + H20(g) > H2(g) + CO(g)
B) Cu(s) + 2Ag+(aq) > Cu2+(aq) + 2Ag(s)

3 answers

A. The pressure since there is more gas on the right side than the left side.
B. Color. The Cu^+2 ion is blue. All of the other materials (in solution) are colorless.
ohhhh ! yes #2 makes perfect sense.

but, how would you test for pressure?
a burning splint test?
Hook a pressure gauge up to the enclosed vessel. As the reaction proceeds the pressure will increase.