Experiment 6 Electrical Conductivity of Aqueous Solutions PDF

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Experiment 6: Electrical Conductivity of Aqueous Solutions: Electrolytes and Nonelectrolytes

Title: Electrical Conductivity of Aqueous Solutions: Electrolytes and Nonelectrolytes. Purpose: Define samples are ionic or molecular; Define samples are acid, base, salt or none. Define samples are electrolyte, nonelectrolyte, strong or weak electrolyte.

Introduction: An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. Electrolytes are salts or molecules that ionize completely in solution. As a result, electrolyte solutions readily conduct electricity. Nonelectrolytes do not dissociate into ions in solution; nonelectrolyte solutions do not, therefore, conduct electricity. Because of the limited number of ions, solutions of weak electrolytes do not conduct electricity as well as strong electrolytes.

Materials Use: Conductivity apparatus, 50 mL beaker, different pure compounds or solutions.

Safety Precautions: 1. Wear safety glasses lab coat, gloves in the lab. 2. pay attention to safety with electricity.

Procedure:

1. Set up the conductivity apparatus, making sure that the switch on the light bulb wire was off. 2. Fill a 50 mL beaker halfway with the compound to be tested and immerse the electrodes of the light bulb assembly into the compound or solution in the beaker. Turn

on the switch of the light bulb. 3. Observations were recorded on the datasheet classifying each compound as a strong electrolyte, weak electrolyte, or nonelectrolyte based on its conductivity behavior. Record the data. 4. Rinse the electrodes with deionized water. 5. Repeat operation.

Calculation and Rusults: Data Sheet Name, formula (state)

Ionic or molecular

(common name)

Acid, base, salt, or

Observation (bright,

Conclusion

none

dim, or no light)

(strong/weak/

Deionized water, H2O

molecular

none

no light

nonelectrolyte nonelectrolyte

(l) Tap water, H2O (l) Sodium chloride,

molecular Ionic

none salt

no light no light

nonelectrolyte -

NaCl (s) (table salt) Sodium chloride,

Ionic

salt

bright light

Strong electrolyte

NaCl (aq) Sodium bicarbonate,

Ionic

salt

no light

-

soda) Sodium bicarbonate,

Ionic

base

no light

Strong electrolyte

NaHCO3 (aq) Sucrose, C12H22O11

molecular

none

no light

-

(table sugar) Sucrose, C12H22O11

molecular

none

no light

nonelectrolyte

(aq) Ethanol,

molecular

none

no light

-

(drinking alcohol) Ethanol,

molecular

none

no light

nonelectrolyte

CH3CH2OH(aq) Glacial acetic acid,

molecular

acid

no light

-

CH3COOH (l) Acetic acid,

Molecular

acid

Dim to bright light

Week to strong

NaHCO3 (s) (baking

(s)

CH3CH2OH(l)

electrolyte

CH3COOH(aq)(5% soln = vinegar) Ammonia, NH3(aq)

molecular

base

Dim to bright light

electrolyte

or NH4OH(aq) (glass cleaner, smelling salts) Hydrochloric acid,

Week to strong

Ionic

acid

bright light

strong electrolyte

acid) Nitric acid, HNO3

Ionic

acid

bright light

strong electrolyte

(aq) Sodium hydroxide,

Ionic

base

bright light

strong electrolyte

Ionic

base

bright light

strong electrolyte

Ionic

base

no light

-

HCl(aq) (muriatic

NaOH(aq) (oven cleaner) Calcium hydroxide, Ca(OH)2(aq) (Tums ®) Magnesium hydroxide, Mg(OH)2 (slurry) (milk of magnesia)

Sources of error Define the light (birth, dim) could be error.

Questions:...