Given the following equation: 2 C4H10 + 13 O2 —> 8 CO2 + 10 H2O, show what the following molar ratios should be.
a. C4H10 / O2
b. O2 / CO2
c. O2 / H2O
d. C4H10 / CO2
e. C4H10 / H2O 2.
The correct answer and explanation is :
The balanced chemical equation for the combustion of butane (C₄H₁₀) is:
2 C₄H₁₀ + 13 O₂ ⟶ 8 CO₂ + 10 H₂O
This equation indicates that 2 moles of butane react with 13 moles of oxygen to produce 8 moles of carbon dioxide and 10 moles of water. The molar ratios between the reactants and products can be determined directly from the coefficients in the balanced equation:
a. C₄H₁₀ / O₂: The ratio of moles of butane to moles of oxygen is 2:13.
b. O₂ / CO₂: The ratio of moles of oxygen to moles of carbon dioxide is 13:8.
c. O₂ / H₂O: The ratio of moles of oxygen to moles of water is 13:10.
d. C₄H₁₀ / CO₂: The ratio of moles of butane to moles of carbon dioxide is 2:8, which simplifies to 1:4.
e. C₄H₁₀ / H₂O: The ratio of moles of butane to moles of water is 2:10, which simplifies to 1:5.
Explanation:
In a balanced chemical equation, the coefficients represent the stoichiometric relationships between reactants and products, indicating the exact proportions in which substances react and are produced. These coefficients are essential for understanding the quantitative aspects of chemical reactions, allowing chemists to predict the amounts of reactants needed and products formed.
For the combustion of butane, the balanced equation shows that 2 moles of C₄H₁₀ react with 13 moles of O₂ to yield 8 moles of CO₂ and 10 moles of H₂O. From this, we can derive the following molar ratios:
- C₄H₁₀ / O₂: The coefficient of C₄H₁₀ is 2, and for O₂, it is 13. Therefore, the molar ratio is 2:13.
- O₂ / CO₂: The coefficient of O₂ is 13, and for CO₂, it is 8, giving a molar ratio of 13:8.
- O₂ / H₂O: The coefficient of O₂ is 13, and for H₂O, it is 10, resulting in a molar ratio of 13:10.
- C₄H₁₀ / CO₂: The coefficient of C₄H₁₀ is 2, and for CO₂, it is 8. Simplifying the ratio 2:8 gives 1:4.
- C₄H₁₀ / H₂O: The coefficient of C₄H₁₀ is 2, and for H₂O, it is 10. Simplifying the ratio 2:10 gives 1:5.
Understanding these molar ratios is crucial in stoichiometric calculations, which involve determining the quantities of reactants and products in chemical reactions. For instance, if a chemist knows the amount of butane available, they can use these ratios to calculate the exact amount of oxygen required for complete combustion, as well as the amounts of carbon dioxide and water that will be produced.
These ratios also have practical implications in industrial processes where butane is used as a fuel. Ensuring the correct proportions of butane and oxygen can optimize combustion efficiency, reduce waste, and minimize the production of unwanted byproducts. Moreover, understanding the amounts of carbon dioxide and water produced is essential for environmental considerations, such as assessing greenhouse gas emissions and designing appropriate mitigation strategies.
In summary, the molar ratios derived from the balanced chemical equation provide a foundational understanding of the quantitative relationships in the combustion of butane, enabling precise calculations and informed decisions in both laboratory and industrial settings.