Which of the following best illustrates the use of gas stoichiometry in a real-world application?

• A. Determining the melting point of NaCl in a laboratory setting.
• B. Measuring the pH of a solution using litmus paper.
• C. Calculating the volume of O_2 needed to completely combust C_2H_6 in an industrial furnace.
• D. Identifying the color change in a precipitation reaction.

Answer: (C)

Verified step by step guidance

1. Understand that gas stoichiometry involves using balanced chemical equations to relate volumes of gases involved in a reaction under the same conditions of temperature and pressure.
2. Identify the chemical reaction involved in the problem, for example, the combustion of ethane (C_2H_6) with oxygen (O_2): \(\mathrm{2\ C_2H_6 + 7\ O_2 \rightarrow 4\ CO_2 + 6\ H_2O}\).
3. Use the mole ratio from the balanced equation to relate the amount of ethane to the amount of oxygen required for complete combustion.
4. Apply the ideal gas law or the concept that equal volumes of gases at the same temperature and pressure contain equal numbers of moles to convert moles of oxygen to volume of oxygen gas needed.
5. Recognize that this calculation is a practical example of gas stoichiometry because it directly relates volumes of gases in a chemical reaction, which is essential in industrial processes like combustion.