Exercise 2: Gas And Reactions Data Table 2 Carbon Dioxide Re ✓ Solved

Exercise 2 Gas And Reactionsdata Table 2carbon Dioxide Reaction Obse

Exercise 2: Gas and Reactions Data Table 2. Carbon Dioxide Reaction Observations. Please be specific and detailed Reaction Observations Ca(OH)2 + CO2 Gas bubbles appeared almost immediately. Solution became opaque white in color. CO2 + BTB Bubbles formed and solution changes color from blue to yellow/copper CO2 + Flame The flame went out almost immediately. Ca(OH)2 + Antacid/water gas Antacid/water gas + Smoldering toothpick Ca(OH)2 + Breath Solution turns lightly opaque and milky in appearance

Questions

  1. Write a balanced chemical equation (with phases) for the reaction of carbon dioxide and limewater (Ca(OH)2). What are the physical descriptions of the products that are formed (i.e., what do they look like)?
  2. When the bromothymol blue (BTB) was exposed to the CO2 gas, what color was the solution? Did the color indicate presence of an acid or base? Explain how you know this.
  3. Did the reaction between the antacid tablet and the tap water produce hydrogen, oxygen, or carbon dioxide gas? Using your results from Exercise 1 and Exercise 2, explain how you came to deduce the identity of the gas that was formed. Be specific.
  4. Based on your observation of the reaction that occurred when limewater was exposed to your breath, what gas did you exhale? Using your observations from Data Table 2, explain how you came to deduce the identity of the gas. Be specific.
  5. What is another simple way to generate carbon dioxide gas?
  6. Carbon dioxide is used in certain types of fire extinguishers. Based on what you learned in this lab, what would happen if the extinguisher was filled with oxygen gas? What about hydrogen gas?

Sample Paper For Above instruction

The reactions involving carbon dioxide are fundamental in understanding acid-base chemistry and gas behavior in chemical reactions. When carbon dioxide interacts with limewater, a well-known test for CO2, a chemical reaction occurs producing calcium carbonate, which is visible as a white precipitate. This reaction is represented by the balanced equation:

Ca(OH)₂ (aq) + CO₂ (g) → CaCO₃ (s) ↓ + H₂O (l)

The calcium carbonate precipitates out of solution as a solid that appears as a cloudy, white suspension, causing the solution to turn opaque. The immediate appearance of bubbles indicates the rapid evolution of CO2 gas during this reaction.

Bromothymol blue (BTB) is an acid-base indicator that changes color depending on the pH of the solution. When exposed to CO2, which forms carbonic acid in water, the solution turns from blue (alkaline) to yellow, indicating an acid present in the solution. This color change confirms the formation of an acid, as CO2 dissolves in water to produce carbonic acid:

CO₂ + H₂O → H₂CO₃

The reaction between an antacid tablet and water primarily produces carbon dioxide gas, evidenced by the bubbling observed during the experiment. The characteristic gas is identified based on its ability to turn limewater milky, react with acids to produce CO2, and produce observable bubbling. The gas carbon dioxide is confirmed by the reaction with limewater and its role in acid-base reactions, as seen with the antacid reacting with water to neutralize stomach acid or other acidified liquids.

When observing the reaction of limewater exposed to breath, the gas exhaled was carbon dioxide. This deduction is based on the milky appearance of limewater, which occurs when CO2 reacts with calcium hydroxide to form calcium carbonate:

Ca(OH)₂ + CO₂ → CaCO₃ ↓ + H₂O

This confirms that CO2 is the exhaled gas, as it is a natural byproduct of respiration. Other methods to generate CO2 include the reaction of acids with carbonate salts or the combustion of hydrocarbons in oxygen-deficient conditions, producing CO2 as a combustion product.

In fire safety applications, carbon dioxide is used to suffocate fires by displacing oxygen, preventing combustion. If an extinguisher filled with oxygen gas were used, the fire would likely intensify, as oxygen sustains combustion. Similarly, hydrogen gas, being highly flammable and explosive, would exacerbate fire hazards if used in a fire extinguisher context, potentially causing explosion rather than extinguishing the flames.

Overall, these experiments highlight the reactive nature of carbon dioxide and its importance in industrial, environmental, and safety applications, emphasizing the need to understand its interactions with various substances and gases.

References

  • Chang, R. (2010). Chemistry (10th ed.). McGraw-Hill Education.
  • Chang, R., & Goldsby, K. (2016). Chemistry (12th ed.). McGraw-Hill Education.
  • Brown, T. L., LeMay, H. E., Bursten, B. E., Murphy, C., & Woodward, C. (2014). Chemistry: The Central Science (13th ed.). Pearson.
  • Atkins, P., & de Paula, J. (2014). Physical Chemistry (10th ed.). Oxford University Press.
  • Zumdahl, S. S., & Zumdahl, S. A. (2014). Chemistry: An Atoms First Approach. Cengage Learning.
  • University of California, Berkeley. (n.d.). Gas Tests in the Laboratory. Berkeley.edu.
  • National Institute of Standards and Technology. (n.d.). Fire Extinguishing Agents. NIST.gov.
  • American Chemical Society. (2020). The Chemistry of Fire Extinguishers. ChemMatters.
  • Gordon, R. J. (2013). Environmental Chemistry and Policy. Wiley.
  • Environmental Protection Agency. (2018). Safety and Use of Fire Extinguishers. EPA.gov.

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