Moles Of Oxygen Needed For Reaction With 27.4 Moles Of H2

by Alex Johnson 58 views

Introduction

In the fascinating world of chemistry, understanding how different elements react with each other is crucial. This article delves into a specific chemical reaction: the combination of hydrogen (H2) and oxygen (O2) to form water (H2O). We'll focus on determining the exact amount of oxygen needed to react completely with a given amount of hydrogen. Specifically, we will address the question: How many moles of oxygen (O2) are required to completely react with 27.4 moles of hydrogen (H2) in the reaction 2 H2 + O2 -> 2 H2O? This is a classic stoichiometry problem that highlights the importance of balanced chemical equations and mole ratios. Mastering these concepts is essential for anyone studying chemistry, whether you're a student or a professional. So, let's embark on this chemical journey to unravel the mysteries of this fundamental reaction and understand the quantitative relationships between reactants and products.

The Balanced Chemical Equation: 2 H2 + O2 → 2 H2O

At the heart of any stoichiometric calculation lies the balanced chemical equation. For the reaction between hydrogen and oxygen to produce water, the balanced equation is:

2 H2 + O2 → 2 H2O

This equation tells us a great deal about the reaction. It indicates that two molecules of hydrogen (H2) react with one molecule of oxygen (O2) to produce two molecules of water (H2O). More importantly, it provides the mole ratios. In chemical reactions, the mole ratio is a fundamental concept that allows chemists to determine the quantitative relationships between reactants and products. It is derived directly from the coefficients in the balanced chemical equation. For example, in the reaction 2 H2 + O2 → 2 H2O, the mole ratio between hydrogen (H2) and oxygen (O2) is 2:1, meaning that for every 2 moles of H2 that react, 1 mole of O2 is required. Similarly, the mole ratio between H2 and H2O is 2:2, or 1:1, indicating that 2 moles of H2 produce 2 moles of H2O. These ratios are crucial for calculating the amount of reactants needed or the amount of products formed in a chemical reaction. Understanding and applying mole ratios correctly is essential for accurate stoichiometric calculations and for predicting the outcomes of chemical reactions. Let's delve deeper into how we can use this information to solve our specific problem.

Understanding these ratios is key to solving stoichiometry problems. The coefficients in front of each chemical formula represent the number of moles of that substance involved in the reaction. In this case, for every 2 moles of H2, 1 mole of O2 is required for a complete reaction.

Determining the Mole Ratio

The mole ratio is the ratio between the amounts in moles of any two chemical species involved in a chemical reaction. It's derived directly from the coefficients in the balanced equation. In our reaction:

2 H2 + O2 → 2 H2O

The mole ratio between H2 and O2 is 2:1. This means that for every 2 moles of H2, we need 1 mole of O2.

Calculating Moles of O2 Required

Now, let's calculate how many moles of O2 are needed to react with 27.4 moles of H2. We use the mole ratio we just identified.

  • We have 27.4 moles of H2.
  • The ratio of H2 to O2 is 2:1.

To find the moles of O2, we set up a proportion:

(Moles of O2) / (Moles of H2) = (1 mole O2) / (2 moles H2)

Plugging in the given value:

(Moles of O2) / 27.4 moles = 1 / 2

Moles of O2 = (27.4 moles) / 2 = 13.7 moles

Therefore, 13.7 moles of O2 are required to completely react with 27.4 moles of H2. This calculation underscores the importance of using mole ratios from balanced chemical equations to accurately determine the amounts of reactants needed in a chemical reaction. By understanding these relationships, we can predict and control the outcomes of chemical processes. Now, let's solidify our understanding by looking at some practice problems and real-world applications of stoichiometry.

Practice Problems and Real-World Applications

To further solidify your understanding of stoichiometry and mole ratios, let's consider a few practice problems and explore some real-world applications. This will help you see how these concepts are used in various contexts, from industrial chemistry to everyday life.

Practice Problems

  1. If you have 5 moles of O2, how many moles of H2 are needed to react completely?

    • Using the mole ratio 2:1 (H2:O2), you would need 10 moles of H2.

  2. How many moles of H2O will be produced if 15 moles of H2 react with sufficient O2?

    • The mole ratio between H2 and H2O is 2:2 or 1:1. Therefore, 15 moles of H2 will produce 15 moles of H2O.

Real-World Applications

  1. Industrial Chemistry: Stoichiometry is crucial in industrial chemistry for optimizing chemical reactions. For instance, in the Haber-Bosch process, nitrogen and hydrogen react to produce ammonia, a key ingredient in fertilizers. Chemists use stoichiometry to determine the precise amounts of reactants needed to maximize ammonia production while minimizing waste.

  2. Automotive Industry: In the automotive industry, stoichiometry plays a vital role in engine design and emission control. The air-fuel mixture in an engine must be carefully controlled to ensure efficient combustion and reduce harmful emissions. Stoichiometric calculations help engineers determine the optimal ratio of air to fuel for complete combustion.

  3. Pharmaceuticals: Stoichiometry is essential in the pharmaceutical industry for synthesizing drugs. Precise amounts of reactants are needed to ensure the correct chemical reactions occur and to avoid unwanted byproducts. This is critical for producing safe and effective medications.

  4. Environmental Science: Stoichiometry is used in environmental science to understand and mitigate pollution. For example, it can help determine the amount of a chemical needed to neutralize an acidic spill or to treat wastewater. By understanding the stoichiometry of chemical reactions, scientists can develop effective strategies for environmental remediation.

  5. Everyday Life: Stoichiometry even has applications in everyday life, such as cooking and baking. When following a recipe, you are essentially using stoichiometry to ensure the correct proportions of ingredients. For example, if a recipe calls for a 2:1 ratio of flour to sugar, you are applying stoichiometric principles to achieve the desired outcome.

By exploring these practice problems and real-world applications, you can see how stoichiometry is not just a theoretical concept but a practical tool used in various fields. Understanding mole ratios and stoichiometric calculations allows us to predict and control chemical reactions, making it an invaluable skill for chemists and scientists alike.

Conclusion

The correct answer is B. 13.7 mol. Understanding stoichiometry and mole ratios is crucial for solving chemistry problems. By correctly interpreting the balanced chemical equation, we can accurately determine the amount of reactants needed for a complete reaction.

For further learning and to deepen your understanding of stoichiometry, you can explore resources like Khan Academy's Chemistry section.