Question

make sure you can read
in each trial, you will add an indicator to the mystery food sample. but you will also add the indicator to a known substance and water. why is that important? check all reasons.
to practice measuring volume using the graduated pipette correctly
to match the mystery food sample to a definite positive result (gelatin, oil, etc.)
to match the mystery food sample to a definite negative result (water)
to increase the amount of data.
done

Explanation:

Answer:

to match the mystery food sample to a definite positive result (gelatin, oil, etc.)
to match the mystery food sample to a definite negative result (water)