Jennifer Liu

2-1

January 19, 2011

Evelyn Korompai

Acid-Base Titration

It was found that when titrating hydrochloric acid with sodium hydroxide, the moles of both compounds are equal, and the molarity of hydrochloric acid is 0.29M.

Purpose:

To titrate hydrochloric acid with sodium hydroxide and to find the molarity of sodium hydroxide.

Materials:

Apparatus

Suction bulb

2 delivery pipets (10 mL)

2 Erlenmeyer flasks (250 mL)

buret

buret clamp and stand

Safety goggles

Reagents

Standardized NaOH solution (approx. 0.52M)

Unknown HCl solution

Phenolphthalein solution

Procedure:

PART 1- DETERMINATION OF MOLARITY OF HYDROCHLORIC ACID SOLUTION

. Put on safety goggles

2. Obtain about 50 mL of the hydrochloric acid solution of unknown concentration and about 100 mL of the standardized NaOH solution. Record the molarity of NaOH in Table 1 .

3. Rinse your pipet with a small amount of HCl first. Then, using a suction bulb, pipet 10.0 mL of the HCl solution into a 250 mL Erlenmeyer flask

4. Add 3 drops of phenolphthalein solution.
Join now!


5. Rinse a clean buret with approximately 15 mL of the standardized NaOH solution. Drain the buret and refill with standardized NaOH solution. Record the initial volume of the NaOH in the buret in Table 1.

6. Gradually dispense some of the standardized NaOH solution into the titration flask. Swirl the flask constantly. (See figure 20C-1). Continue adding NaOH, noting any changes in the flask.

7. As the equivalence point is approached, a pinkish color will appear, and dissipate more slowly as the titration proceeds. Now add the NaOH drop by drop. Stop the titration ...

This is a preview of the whole essay