Ascientist wants to test how much of an acid can be added to a solution before
the ph of the solution changes to below a certain point. the starting ph of the
solution is 6.0, and the scientist wants to know when the ph of the solution
changes to below 4.0.
which ph indicator should the scientist use?
a
cresol red, which changes from yellow to purple around a ph of 7.2
b. thymolphthalein, which changes from colorless to blue around a ph of
9.3
c. methyl yellow, which changes from yellow to red around a ph of 4.0
d. methyl violet, which changes from violet to yellow around a ph of 2.0