Name ________________________________ Period ____________Chemistry I Date _____________

Indicators Lab

Purpose: Use various indicators to classify solutions as acids, bases, or neutral.

Procedure:

1. Use a well plate. Be sure to clean it thoroughly before beginning lab.2. Add ten drops of acetic acid solution to three horizontal wells.3. Test the first well with a strip of red litmus paper and then blue litmus paper using tweezers. Record results in the table.4. To the first well, add one drop of phenolphthalein. Record results in the table.5. To the second well, add one drop of bromothymol blue. Record results in the table.6. To the third well, add one drop of methyl-orange. Record results in the table.7. Repeat steps 2-7 with each of the samples. Make sure you do not confuse the samples.

Pre-lab Questions

1. What is an indicator? Name three examples used in this lab.

2. What is an electrolyte? What three substances are usually electrolytes?

3. Predict whether water is acidic, basic or neutral. Why?

Data

Solution Formula Red litmus Blue litmus Phenoph-thalein

Bromothymol blue

Methyl orange A-B-N

Acetic acid HC2H3O2

Ammonia NH3

Lemon Juice

Isopropyl alcohol C3H7OH

Magnesium sulfate MgSO4

Salt water NaCl

Sodium hydroxide(drano)

NaOH

Sucrose C12H22O11

Water H2O

Baking Soda NaHCO3

Sprite

Indicators Acid Base Neutral

Red litmus paper Red Blue Red

Blue litmus paper Red blue Blue

Phenolphthalein Clear Bright pink Clear

Methyl orange Red orange NA

Bromothymol blue Yellow Blue Green