Chapter Name: Acids, Bases and Salts
Activity Name: When acid reacts with metal H2 gas is evolved in Acids, Bases and Salts
In this experiment, students investigate the reactions between dilute acids (HCl, H2SO4, HNO3) and metal zinc granules. The objective is to observe the evolution of hydrogen gas when acids react with metals.
- Test tube, delivery tube, glass trough, candle, soap water, dilute HCl, and zinc granules.
Step by Step Procedure:
- Set up the apparatus as shown in figure 1.
- Take approximately 10ml of dilute HCl in a test tube.
- Add a few zinc granules to the test tube containing HCl.
- Observe the surface of the zinc granules for any changes.
- Pass the gas being evolved through the soap water.
- Observe the formation of bubbles in the soap solution.
- Carefully bring a burning candle near the gas-filled bubble.
- Observe any reactions and record the findings.
- On the surface of the zinc granules, you will notice effervescence (bubbles) as the zinc reacts with the acid.
- Bubbles will form in the soap solution due to the passage of the evolved gas (hydrogen) through it.
- When a burning candle is brought near the gas-filled bubble, it will ignite with a pop sound, indicating the presence of hydrogen gas.
- Perform the experiment in a well-ventilated area or under a fume hood.
- Handle the dilute acids with care and avoid contact with skin or eyes.
- Use appropriate safety equipment, such as gloves and safety goggles.
- Keep the flame of the candle at a safe distance from the gas-filled bubble to prevent any accidents.
Lesson Learnt from Experiment:
The experiment demonstrates that when dilute acids react with metals, hydrogen gas is evolved. This reaction is characterized by the effervescence of the metal surface and the ignition of hydrogen gas with a pop sound when exposed to a flame. Students learn about the formation of hydrogen gas and the characteristic properties of this chemical reaction.