PREPARATION OF AN INDICATOR AND AN ACID/BASE TITRATIO

Chem lap quiz #5

Goals (3):

1. Preparation acid/base indicator from cabbage.

2. Gaining practice in acid/base titration technique.

3. Find the molarity of unknown Calcium Hydroxide solution.

5 materials:

1. erlenmeyer flask

2. beakers

3. filter paper (77mm)

4. burette

5. pipette

chemicals

1. red cabbage

2. pH 7 buffer

3. HCI acid solution.

4. unknown solution molarity.

what kind of water do you use to boil the gabbage?

distilled water.

what do you do with the filtrate?

save and use as an indictor.

why do we dispose the boiled cabbage in the cabbage waste container?

it will begin to decompose and smell.

What are the (3) procedures?

1. Preparation of the indicator from cabbage

2. Titration with phenolphthalein as the indicator

3. Titration with the cabbage

what happens if you add much too much of the solution on the last step?

solution will turn pink if you add to much acid.

what is the equation to calculate the molarity/pH of the hydrochloric acid solution?

pH= -log H+

what calculation do you use to calculate each of the accurate titrations?

Ca (OH)2