Praktikum Hukum Lavoisier ( Kekekalan Massa ) Hukum Dasar Kimia Kelas X

Summary

This educational video demonstrates the Law of Conservation of Mass through two chemistry experiments. In the first, potassium iodide reacts with lead nitrate, and in the second, sodium carbonate reacts with calcium chloride. Both experiments show that despite the formation of new compounds, the mass of the reactants before and after the reaction remains unchanged, proving Lavoisier's law. The video explains the methodology of measuring solutions, conducting reactions, and observing color changes as indicators, ultimately reinforcing the principle that mass is conserved in chemical reactions.

Takeaways

• 😀 Lavoisier's Law states that mass in a closed system remains constant during chemical reactions.
• 😀 The script involves a practical experiment to prove the Law of Conservation of Mass in chemistry.
• 😀 The first experiment uses Potassium iodide (KI) and Lead nitrate (Pb(NO₃)₂), showing a color change from clear to yellow.
• 😀 In the second experiment, Calcium chloride (CaCl₂) and Sodium carbonate (Na₂CO₃) react, causing a color change from clear to white.
• 😀 Both experiments confirm that the mass before and after the reaction remains the same, supporting Lavoisier's Law.
• 😀 Mass measurement is taken using a digital balance before and after the chemical reactions in both experiments.
• 😀 Proper measurement techniques, like ensuring the eye level with the miniscus on a graduated cylinder, are highlighted for accuracy.
• 😀 The change in color during reactions (yellow and white) visually signals the chemical changes occurring in the solutions.
• 😀 The two experiments validate that even when chemical reactions produce new substances, the mass is conserved.
• 😀 The experiments aim to help viewers understand the application of Lavoisier's Law in real-life chemical reactions.

Q & A

What is the purpose of the experiment demonstrated in the video?

The purpose of the experiment is to demonstrate and prove Lavoisier's Law of Conservation of Mass using two chemical reactions in the laboratory.

What is Lavoisier's Law of Conservation of Mass?

Lavoisier's Law, also known as the Law of Conservation of Mass, states that in a closed system, the mass remains constant before and after a chemical reaction, meaning that the mass of the reactants equals the mass of the products.

What substances are used in the first experiment?

In the first experiment, the substances used are potassium iodide (KI) and lead nitrate (Pb(NO3)2).

What chemical reaction occurs in the first experiment?

In the first experiment, potassium iodide (KI) reacts with lead nitrate (Pb(NO3)2) to form lead(II) iodide (PbI2), a yellow precipitate.

What is observed when the two solutions in the first experiment are mixed?

When the potassium iodide solution and lead nitrate solution are mixed, a yellow precipitate of lead(II) iodide (PbI2) forms, indicating the occurrence of a chemical reaction.

What measurements are taken before and after the reactions?

The mass of the solutions before and after the reactions is measured using a digital balance to verify if the mass remains the same, which supports Lavoisier's Law.

What happens in the second experiment?

In the second experiment, sodium carbonate (Na2CO3) is reacted with calcium chloride (CaCl2) to produce calcium carbonate (CaCO3), a white precipitate.

How are the masses in the second experiment compared?

As in the first experiment, the mass of the solutions before and after the reaction is measured, and it is found that the mass remains the same, confirming the Law of Conservation of Mass.

What does the result of both experiments prove?

The results of both experiments show that the mass of the system before and after the reaction remains the same, thereby proving Lavoisier's Law of Conservation of Mass.

What should one ensure when measuring the liquids with a graduated cylinder?

When measuring liquids with a graduated cylinder, it is important to ensure that the eye level is aligned with the meniscus to accurately read the scale of the liquid level.