Acid – base (Neutralization) reaction in Acids, Bases and Salts – Class 10 Science Experiment

Chapter Name: Acids, Bases and Salts

Activity Name: Acid – base (Neutralization) reaction in Acids, Bases and Salts

Activity Description:

In this experiment, we will explore the concept of neutralization reactions between an acid and a base. We will use dilute NaOH (sodium hydroxide) solution and dilute HCl (hydrochloric acid) solution to observe the color changes and understand the formation of salts and water during the reaction.

Required Items:

1. Dilute NaOH solution
2. Dilute HCl solution
3. Phenolphthalein indicator
4. Test tubes
5. Dropper

Step by Step Procedure:

1. Take about 2 ml of dilute NaOH solution in a test tube.
2. Add one drop of phenolphthalein indicator to the NaOH solution and observe the color of the solution (should be pink).
3. Start adding dilute HCl solution drop by drop to the NaOH solution and observe any changes in color.
4. Note the point where the pink color disappears, indicating neutralization.
5. Now, add one or two drops of NaOH solution again to the mixture.
6. Observe if the pink color reappears and note your observations.

Experiment Observations:

• Initially, the NaOH solution with phenolphthalein indicator is pink.
• As HCl is added, the pink color disappears, indicating a neutralization reaction.
• After adding a few drops of NaOH again, the pink color may reappear.

Precautions:

1. Handle the acids and bases with care and use appropriate safety measures, such as wearing gloves and goggles.
2. Use dilute solutions to avoid any strong reactions or accidents.
3. Perform the experiment in a well-ventilated area.

Lesson Learnt from Experiment:

The experiment demonstrates the concept of neutralization reactions, where an acid and a base react to form a salt and water, neutralizing each other’s properties. The disappearance and reappearance of the pink color indicate the completion of the neutralization reaction.