Praktikum Kimia Dasar Modul 3. Gas dan Kinetika Gas

Summary

In this video, the experiment focuses on determining the molar mass of a volatile liquid and calculating the volume of CO2 produced in a reaction between calcium carbonate (CaCO3) and hydrochloric acid (HCl). The first part involves heating the liquid in an Erlenmeyer flask, measuring its mass before and after evaporation, and calculating its molar mass. The second part demonstrates the reaction of CaCO3 with HCl to produce CO2, with gas volume measured through water displacement. Data such as temperature and pressure are recorded to facilitate accurate calculations, reinforcing the principles of gas laws and molar volumes.

Takeaways

• 😀 The first experiment involves determining the molar mass of a volatile liquid by measuring its mass, volume, and temperature.
• 😀 The volatile liquid is evaporated using a hotplate, and the mass of the flask is measured before and after evaporation to calculate the molar mass.
• 😀 A barometer is used to measure the pressure (754 mmHg) during the experiment, which is necessary for gas law calculations.
• 😀 The volume of the Erlenmeyer flask is measured by filling it with water and using a graduated cylinder, which is important for calculating the molar volume of gas.
• 😀 In the second experiment, calcium carbonate (CaCO3) reacts with hydrochloric acid (HCl) to produce CO2 gas, which is collected and measured.
• 😀 The reaction between CaCO3 and HCl is represented by the equation: CaCO3 + 2HCl → CaCl2 + CO2 + H2O.
• 😀 The gas volume is measured through water displacement in a graduated cylinder, allowing for the calculation of CO2's molar volume under given conditions.
• 😀 Temperature and pressure must be carefully controlled and measured during the experiment to accurately apply the ideal gas law for volume calculations.
• 😀 After the CO2 reaction, the mass of the remaining solid and liquid is measured to confirm the amount of gas produced and the efficiency of the reaction.
• 😀 Final calculations involve determining the percentage of CaCO3 in the mixture and comparing theoretical versus actual CO2 volume produced during the reaction.

Q & A

What is the objective of the experiment in this script?

The objective of the experiment is to determine the molar mass of a volatile liquid and to study gas laws, specifically the relationships between pressure, volume, and temperature.

What is the first procedure described in the script?

The first procedure involves determining the molar mass (Mr) of a volatile liquid by measuring the mass before and after evaporation, as well as measuring the gas volume and pressure during the experiment.

Why is it important to weigh the Erlenmeyer flask both before and after the experiment?

Weighing the Erlenmeyer flask before and after the experiment allows us to determine the mass of the volatile liquid that has evaporated, which is crucial for calculating the molar mass of the liquid.

What role does the hotplate play in the procedure?

The hotplate is used to heat the Erlenmeyer flask containing the volatile liquid, causing the liquid to evaporate so that we can measure the amount of gas produced and complete the experiment.

How is the volume of the Erlenmeyer flask measured in the experiment?

The volume of the Erlenmeyer flask is measured by filling it with water and using a graduated cylinder to calculate the total volume based on the water displacement.

How is atmospheric pressure measured in the experiment?

Atmospheric pressure is measured using a barometer, and in the script, the recorded pressure is 754 mmHg.

What chemical reaction is used in the second procedure to generate CO2?

In the second procedure, the reaction between calcium carbonate (CaCO3) and hydrochloric acid (HCl) produces CO2 gas, which is collected and measured.

How is the amount of CO2 gas measured during the experiment?

The amount of CO2 gas is measured by displacing water from a graduated cylinder submerged in an overflow container. The volume of gas produced is recorded based on the water displacement.

What is the significance of calculating the molar mass of the volatile liquid?

Calculating the molar mass of the volatile liquid allows us to understand its physical properties and its behavior when it evaporates, providing insight into its molecular structure.

What calculations are necessary for determining the theoretical and experimental volume of CO2 produced?

To calculate the theoretical volume of CO2, you must first determine the moles of CO2 gas using the ideal gas law and the conditions of pressure and temperature. The experimental volume is determined by measuring the volume of CO2 produced during the reaction and comparing it with the theoretical value.