Question 1: Explain why Carbon Dioxide is considered a colorless and odorless gas. Include its common sources in daily life.

Answer: Carbon Dioxide is colorless and odorless because it is a simple molecular gas with no visible color or smell. Common sources include respiration, combustion of fossil fuels, and volcanic activity.

Question 1: Describe the chemical test used to identify Carbon Dioxide in a gas sample.

Answer: The test involves passing the gas through limewater; if Carbon Dioxide is present, limewater turns milky or cloudy due to the formation of calcium carbonate.

Question 2: Explain the mechanism behind the limewater test for Carbon Dioxide.

Answer: When Carbon Dioxide reacts with limewater (calcium hydroxide), it forms calcium carbonate, which is insoluble and causes the solution to turn cloudy, indicating the presence of CO2.

Question 1: Calculate the volume of Carbon Dioxide produced at standard temperature and pressure (STP) when 5 grams of calcium carbonate (CaCO3) decomposes. (Molar mass of CaCO3 = 100 g/mol, 1 mol CaCO3 produces 1 mol CO2).

Answer: Step 1: Calculate moles of CaCO3: 5 g / 100 g/mol = 0.05 mol. Step 2: Moles of CO2 produced = 0.05 mol. Step 3: Volume of 1 mol of gas at STP = 22.4 L. Step 4: Volume of CO2 = 0.05 mol × 22.4 L/mol = 1.12 L.

Question 1: Describe a safe method to collect Carbon Dioxide gas in a laboratory setting during an experiment.

Answer: Carbon Dioxide can be collected over limewater in a test tube fitted with a delivery tube, ensuring proper ventilation and avoiding inhalation of concentrated CO2. Use safety goggles and gloves.

Question 2: Identify the variables that need to be controlled during the experiment to test for Carbon Dioxide using limewater.

Answer: Variables to control include the amount of limewater used, the temperature of the reaction, and the flow rate of the gas passing through limewater.

Question 1: In an experiment, 50 mL of a gas sample turns limewater cloudy. If the initial volume of limewater was 100 mL and after passing the gas, it remained at 100 mL with no further change, what does this indicate about the gas sample?

Answer: It indicates that the gas sample contains Carbon Dioxide, as it reacts with limewater to produce calcium carbonate, causing cloudiness without consuming limewater volume.

Question 1: Explain why Carbon Dioxide is used in fire extinguishers. Include the properties that make it effective.

Answer: Carbon Dioxide is used in fire extinguishers because it is heavier than air, displaces oxygen around the fire, and is non-flammable. Its ability to rapidly cool and suffocate flames makes it effective for extinguishing fires without causing harm to the environment or leaving residue.

Question 1: Discuss the role of Carbon Dioxide in carbonated beverages and the science behind the fizz.

Answer: Carbon Dioxide is dissolved under pressure in beverages; when opened, the pressure decreases, and CO2 escapes as bubbles, creating the fizz. This process relies on the gas's solubility and release upon opening.