Question

2. What conclusions can you draw about the identities of the gases (CO2) produced in each chemical reaction? Write an evidence-based claim.

Answer 1

Conclusions about the identity of carbon dioxide in chemical reactions can be drawn from the conditions of formation, such as being a product of combustion, and from the enthalpy change being indicative of an exothermic process. The stoichiometry of the reactions provides additional evidence.

Step-by-step explanation:

When considering the chemical reactions that produce carbon dioxide (CO2), we can draw conclusions based on the evidence of these reactions.

Carbon dioxide is typically formed when carbon-containing substances oxidize; for instance, the combustion of hydrocarbons in oxygen results in carbon dioxide and water

Furthermore, according to Hess's Law, the formation of CO2 from carbon and oxygen is an exothermic process, indicating that the products (including CO2) have lower enthalpy than the reactants, which is evidence of energy release during the formation of carbon dioxide.

To understand the quantities involved in reactions producing CO2, one should note that enthalpy change (ΔH) is directly proportional to the quantities of reactants or products.

For example, the balancing of chemical equations is crucial when assessing the formation of CO2. A combustion reaction may show that more moles of oxygen are consumed compared to the carbon dioxide produced, illustrating the stoichiometry of the reaction and the resulting changes in the gas volumes.

Answer 2

By following these steps, you can systematically identify CO₂ in chemical reactions and make evidence-based claims about its presence.

To draw conclusions about the identity of carbon dioxide (CO₂) produced in chemical reactions, you should follow a systematic approach. Here's a step-by-step guide to help you identify CO₂ and provide evidence-based claims:

Step 1: Understanding the Basics of CO₂

- Chemical Formula:CO₂ consists of one carbon atom and two oxygen atoms.

- Properties: It is a colorless, odorless gas at room temperature, and is denser than air.

Step 2: Identifying the Reaction Types

CO₂ can be produced in various types of reactions. Common ones include:

- Combustion: Burning hydrocarbons (like methane, propane) in oxygen.

- Acid-Base Reactions: Reaction between carbonates or bicarbonates and acids.

- Respiration: In biological systems, CO₂ is a byproduct of cellular respiration.

Step 3: Examining the Reaction Equations

For each reaction, write down the balanced chemical equation. For instance:

- Combustion:
`\( C_xH_y + O_2 \rightarrow CO_2 + H_2O \)`

- Acid-Base:
`\( MCO_3 + H_2SO_4 \rightarrow CO_2 + MSO_4 + H_2O \)`(where M is a metal)

Step 4: Performing Experiments

Conduct experiments to see if CO₂ is produced. For instance:

- Limewater Test: Pass the gas through limewater (calcium hydroxide solution). If it turns milky, it indicates the presence of CO₂.

- pH Changes: CO₂ can acidify water, so testing the pH can be indicative.

Step 5: Observing the Results

- If the limewater turns milky, it is a strong indication of CO₂.

- Changes in pH toward acidity when the gas dissolves in water also suggest CO₂.

Step 6: Making an Evidence-Based Claim

Based on the experiments and observations, you can make a claim. For example:

- "In the combustion of methane, the formation of a milky precipitate in limewater and the observed decrease in pH when the gas dissolves in water strongly indicate the production of carbon dioxide."

Step 7: Discussing Possible Errors or Alternative Explanations

- Consider other gases that might react similarly and how you can differentiate them.

- Discuss experimental errors that could affect the results.