Answer:
A
Explanation:
A chemical change happens when one chemical substance is transformed into one or more different things , such as when iron becomes rust so
B: Acids turn the indicator red, pink, orange, and yellow, while bases turn it green based on what it reactions with or comes in contact with so b is maybe
c is wrong
and d a physical change, will technically yes and no there should have not been a smell afterwards so the only really choose that makes sense here is A
The answer is A moves molecules. (:
the 2nd one is correct
The option that would most likely increase the rate for a more contentrated potassium hydrogene
:) hope this helps