Which of the following best represents a chemical change? A. Chopping wood
B. Silver tarnishing (changing color)
C. Grape kool-aid mix dissolving in water
D. Dry ice turning into a gas (sublimation- a change of state)

You encounter a solution that is acidic and you decide to test it by adding a small amount of a strong acid. the ph lowers slightly but is approximately unchanged, and still remains acidic. what can you say about the solution? a. it is a buffer solution. b. it is not a buffer solution it is a strong acid solution. d. the solution has been neutralized. e. the solution has excess acid present

Asample of freon gas has a volume of 2.23 liters, a pressure of 4.85 kpa, and a temperature of -1.36°c. calculate the volume at a pressure of 1.38 kpa and a temperature of 5.5°c. (show work)

What is the most common reason for matter changing its state?