To Obtain Common Salt In Pure And Dry State By Neutralization Process. | Grade Xi

APPARATUS REQUIRED

• Beakers (100 ml, 250 ml, 500 ml)
• Funnel
• Filter paper
• Bunsen burner
• Tripod stand
• Wire gauze
• Porcelain crucible
• Tongs
• Glass rod
• Evaporating dish
• Measuring cylinder
• Thermometer
• pH meter (optional)

CHEMICALS REQUIRED

• Sodium hydroxide (NaOH) solution
• Hydrochloric acid (HCl) solution
• Sodium chloride (NaCl) solution
• Distilled water

THEORY

Sodium chloride (NaCl), commonly known as salt, is a compound that can be obtained through a neutralization reaction between sodium hydroxide (NaOH) and hydrochloric acid (HCl). In this process, sodium hydroxide acts as a base, while hydrochloric acid acts as an acid. When these two chemicals are mixed in the right proportions, they react to form sodium chloride and water, as shown in the balanced chemical equation:

NaOH + HCl → NaCl + H2O

PROCESS

1. Prepare 100 ml of 1 M NaOH solution and 100 ml of 1 M HCl solution.
2. Using a pH meter measure the pH of both solutions .
3. Take 50 ml of each solution in two separate beakers.
4. Slowly add the NaOH solution to the HCl solution while stirring constantly.
5. Observe the changes in the temperature of the reaction mixture.
6. Continue adding the NaOH solution until the pH of the mixture becomes neutral (pH = 7).
7. Filter the reaction mixture using a funnel and filter paper to separate the sodium chloride precipitate from the solution.
8. Rinse the filter paper with distilled water to remove any remaining impurities.
9. Transfer the sodium chloride precipitate to an evaporating dish.
10. Heat the evaporating dish gently using a Bunsen burner until all the water evaporates and the sodium chloride becomes dry.
11. Allow the sodium chloride to cool down and then transfer it to a clean container.

OBSERVATIONS

• The reaction mixture will become warm as the reaction takes place.
• If the pH of the mixture is not neutral after adding the NaOH solution, continue adding the NaOH solution until the pH reaches 7.
• The sodium chloride precipitate will appear as a white solid.
• The filtrate will be clear and colorless.

OBSERVATION TABLE

Observation	Explanation
The reaction mixture becomes warm	The reaction between NaOH and HCl is exothermic, meaning it releases heat.
The pH of the mixture changes from acidic to neutral	As NaOH is added, it neutralizes the HCl, increasing the pH of the mixture.
A white solid precipitate forms	This is sodium chloride (NaCl), which is insoluble in water.
The filtrate is clear and colorless	This indicates that all of the NaCl has precipitated out of solution.

CALCULATION

The amount of NaCl produced can be calculated using the following formula:

Mass of NaCl = (Molarity of NaOH solution × Volume of NaOH solution) × (Molecular weight of NaCl / 1000)

RESULTS

The experiment successfully produced sodium chloride (NaCl) in a pure and dry state by the neutralization process. The NaCl was obtained as a white solid precipitate. The filtrate was clear and colorless, indicating that all of the NaCl had precipitated out of solution.

PRECAUTIONS

• Handle NaOH and HCl solutions with care, as they are corrosive.
• Wear protective gloves and eye protection while performing the experiment.
• Do not heat the evaporating dish too strongly, as this may cause the sodium chloride to decompose.
• Allow the sodium chloride to cool down completely before transferring it to a clean container.