Procedure 1: Molar Mass of Volatile Liquid
📌 The first procedure aims to measure the physical properties (pressure, volume, temperature) of a gas to determine the molar mass ($\text{Mr}$) of a volatile liquid sample.
🔬 The initial mass of the empty Erlenmeyer flask, aluminum foil, and rubber band was recorded as 66.752860 grams.
🧪 A fixed volume (5 mL) of the volatile liquid was introduced into the flask, sealed, heated on a hotplate at 85°C until the liquid completely vaporized, and then cooled to room temperature to measure the final mass.
⚖️ The final mass of the flask assembly, containing the residual gas/vapor, was measured as 66.904 grams. The experiment also required recording the atmospheric pressure (754 mmHg) and the volume of the flask (148 mL) for calculation.

Procedure 2: Molar Volume of Carbon Dioxide ($\text{CO}_2$)
⚙️ The second procedure involves generating $\text{CO}_2$ gas from the reaction between Calcium Carbonate ($\text{CaCO}_3$) and Hydrochloric Acid ($\text{HCl}$) to measure the molar volume.
🧮 A theoretical mass of 0.178 grams of $\text{CaCO}_3$ was calculated to produce 40 mL of $\text{CO}_2$ gas at Standard Temperature and Pressure (STP), based on the balanced reaction: $\text{CaCO}_3 + 2\text{HCl} \rightarrow \text{CaCl}_2 + \text{H}_2\text{O} + \text{CO}_2$.
⚗️ $\text{CO}_2$ gas generation utilized a small tube containing $\text{CaCO}_3$ submerged slowly into a larger tube containing 10 mL of 3M HCl (the generator system).
📊 The volume of $\text{CO}_2$ produced was measured by water displacement in an inverted 100 mL graduated cylinder submerged in water, yielding a practical volume of 43 mL.

Key Points & Insights
➡️ Volatile Liquid Measurement: The molar mass calculation requires accurate measurements of initial mass, final mass, vapor temperature, flask volume, and atmospheric pressure (measured at 754 mmHg).
➡️ Gas Generation Setup: Successful $\text{CO}_2$ measurement depends on careful sealing of the generator assembly and ensuring the water level in the measuring cylinder matches the water level in the surrounding basin for accurate pressure equalization.
➡️ Data Analysis Focus: The primary goal for Procedure 2 is to calculate the percentage yield of $\text{CaCO}_3$ in the sample and compare the theoretical volume of $\text{CO}_2$ (calculated from 0.178 g $\text{CaCO}_3$) with the experimental volume (43 mL).

📸 Video summarized with SummaryTube.com on Nov 18, 2025, 14:23 UTC