Experiment 1. Preparation and Standardization of HCl Solution

Primary Standard

Chemically pure solid dissolved in water to form the primary standard solution.

Indicator

substance which changes color at or very near the titration when equivalent amount of the reactants have reache

Standardization

process of determining the exact concentration of a solution

200 mL of distilled water

Preparation of Hydrochloric Acid Solution:

1. Transfer about _______________________ into a 1000-mL beaker.

2. Measure _______________________________________ using a graduated cylinder and slowly add to the distilled water with stirring under the fume hood.

3. Add ___________________________ to make 1 liter.

4. Transfer the hydrochloric acid solution into a ___________________________

5. ________ properly (Date prepared, Grp. no., Name of reagent and its conc. in N and M)

1 = ?

42 mL of concentrated hydrochloric acid solution

Preparation of Hydrochloric Acid Solution:

1. Transfer about _______________________ into a 1000-mL beaker.

2. Measure _______________________________________ using a graduated cylinder and slowly add to the distilled water with stirring under the fume hood.

3. Add ___________________________ to make 1 liter.

4. Transfer the hydrochloric acid solution into a ___________________________

5. ________ properly (Date prepared, Grp. no., Name of reagent and its conc. in N and M)

2 = ?

enough distilled water

Preparation of Hydrochloric Acid Solution:

1. Transfer about _______________________ into a 1000-mL beaker.

2. Measure _______________________________________ using a graduated cylinder and slowly add to the distilled water with stirring under the fume hood.

3. Add ___________________________ to make 1 liter.

4. Transfer the hydrochloric acid solution into a ___________________________

5. ________ properly (Date prepared, Grp. no., Name of reagent and its conc. in N and M)

3 = ?

1L stock bottle (flint bottle)

Preparation of Hydrochloric Acid Solution:

1. Transfer about _______________________ into a 1000-mL beaker.

2. Measure _______________________________________ using a graduated cylinder and slowly add to the distilled water with stirring under the fume hood.

3. Add ___________________________ to make 1 liter.

4. Transfer the hydrochloric acid solution into a ___________________________

5. ________ properly (Date prepared, Grp. no., Name of reagent and its conc. in N and M)

4 = ?

Label

Preparation of Hydrochloric Acid Solution:

1. Transfer about _______________________ into a 1000-mL beaker.

2. Measure _______________________________________ using a graduated cylinder and slowly add to the distilled water with stirring under the fume hood.

3. Add ___________________________ to make 1 liter.

4. Transfer the hydrochloric acid solution into a ___________________________

5. ________ properly (Date prepared, Grp. no., Name of reagent and its conc. in N and M)

5 = ?

Conc. HCl

strong mineral acid, colorless liquid, and corrosive

white fumes

When Conc. HCl is exposed to air, it produces __________________ which is irritating to the nose and lungs when inhaled.

very dilute and only a small amount of heat

You should add acid to water because the solution is ______________________________ will be released, not enough to vaporize and splash out of the container.

boil violently and splash

Do not add water to acid because HCl is very concentrated, adding water to it will release so much heat from the solution which may cause it to ________________________________ out of the container.

exothermic reaction

In short, adding water to concentrated acid will cause an _________________________.

irritating to the nose and lungs

The preparation of the HCl Solution should be done under the fume hood because it is ________________________________ when inhaled.

directly (no intermediate containers)

In transferring the HCl Solution to a flint stock bottle, it should be done __________________

0.4 to 0.5g of anhydrous sodium carbonate

Standardization of the Hydrochloric Acid Solution:

1. Weigh accurately _________________________________into a tared Erlenmeyer flask.
2. Dissolve the sodium carbonate in _______________ and shake until solution is complete.
3. Add _______________________________.
4. Titrate with _________________________ (from burette)
5. Perform ________________. (Group pair, one determination each)

6. Determine the __________________________ of the hydrochloric acid solution.

1 = ?

80mL of distilled water

Standardization of the Hydrochloric Acid Solution:

1. Weigh accurately _________________________________into a tared Erlenmeyer flask.
2. Dissolve the sodium carbonate in _______________ and shake until solution is complete.
3. Add _______________________________.
4. Titrate with _________________________ (from burette)
5. Perform ________________. (Group pair, one determination each)

6. Determine the __________________________ of the hydrochloric acid solution.

2 = ?

2 drops of methyl orange

Standardization of the Hydrochloric Acid Solution:

1. Weigh accurately _________________________________into a tared Erlenmeyer flask.
2. Dissolve the sodium carbonate in _______________ and shake until solution is complete.
3. Add _______________________________.
4. Titrate with _________________________ (from burette)
5. Perform ________________. (Group pair, one determination each)

6. Determine the __________________________ of the hydrochloric acid solution.

3 = ?

hydrochloric acid solution

Standardization of the Hydrochloric Acid Solution:

1. Weigh accurately _________________________________into a tared Erlenmeyer flask.
2. Dissolve the sodium carbonate in _______________ and shake until solution is complete.
3. Add _______________________________.
4. Titrate with _________________________ (from burette)
5. Perform ________________. (Group pair, one determination each)

6. Determine the __________________________ of the hydrochloric acid solution.

4 = ?

2 determinations

Standardization of the Hydrochloric Acid Solution:

1. Weigh accurately _________________________________into a tared Erlenmeyer flask.
2. Dissolve the sodium carbonate in _______________ and shake until solution is complete.
3. Add _______________________________.
4. Titrate with _________________________ (from burette)
5. Perform ________________. (Group pair, one determination each)

6. Determine the __________________________ of the hydrochloric acid solution.

5 = ?

normality and molarity

Standardization of the Hydrochloric Acid Solution:

1. Weigh accurately _________________________________into a tared Erlenmeyer flask.
2. Dissolve the sodium carbonate in _______________ and shake until solution is complete.
3. Add _______________________________.
4. Titrate with _________________________ (from burette)
5. Perform ________________. (Group pair, one determination each)

6. Determine the __________________________ of the hydrochloric acid solution.

6 = ?

Anhydrous Sodium Carbonate

Reagent that is known as the Primary Standard

Anhydrous Sodium Carbonate dissolved in Distilled Water

Reagent that is known as the Primary Standard Solution

Methyl Orange

Reagent that is known as the indicator

Yellow

Color of the primary standard solution when a methyl orange is first added:

Salmon

Color of the primary standard solution when a methyl orange is at its endpoint

Red

Color of the primary standard solution when a methyl orange is over titrated:

Acidic

If the color of the solution is:

a. Red

b. Salmon

c. Yellow

a = ?

Neutral

If the color of the solution is:

a. Red

b. Salmon

c. Yellow

b = ?

Alkali/Basic

If the color of the solution is:

a. Red

b. Salmon

c. Yellow

c = ?

HCl Solution

known as the solution to be titrated

Chemical Reaction of the Standardization of the HCl Solution

𝟏𝑁𝑎2𝐶𝑂3 + 𝟐𝐻𝐶𝑙 → 𝟐𝑁𝑎𝐶𝑙 + 𝐻2𝑂 + 𝐶𝑂2↑

1:2

Ratio of the moles of Sodium Carbonate to the moles Hydrochloric Acid

Primary Standardization

Type of Standardization

Neutralization

Type of Volumetric Analysis

Direct

Type of Titration