Is any acetaminophen leftover?
Add 0.1% FeCl3 to each test tube
Add acetaminophen to one, product to another, and water to the last...
This is why we use a positive control (acetaminophen). That way we can tell if the problem is our product or the test itself.
We know acetaminophen should produce a color change, so we know something must have gone wrong with the test.
Most likely the 0.1% Ferric Chloride is not strong enough to react...
So let's kick it up a notch with some 3% ferric chloride!
What does this tell us about the success of our reaction?