If 6.0 Moles Of Zinc React With 6.0 Moles Of Hydrochloric Acid In The Equation $Zn + 2HCl \rightarrow ZnCl_2 + H_2$, What Is The Limiting Reactant?A. $H_2$ B. $Zn$ C. $ZnCl_2$ D. $HCl$

Mar 1, 2025 by ADMIN 190 views

**Chemical Reactions: Identifying the Limiting Reactant**

Introduction

Chemical reactions involve the interaction of reactants to form products. In many cases, the reactants are present in different quantities, and the limiting reactant is the one that determines the amount of product formed. In this article, we will discuss the concept of limiting reactants and how to identify them using the given chemical equation.

Understanding the Chemical Equation

The given chemical equation is $Zn + 2HCl \rightarrow ZnCl_2 + H_2$ . This equation represents the reaction between zinc (Zn) and hydrochloric acid (HCl) to form zinc chloride (ZnCl_2) and hydrogen gas (H_2). The equation shows that 1 mole of zinc reacts with 2 moles of hydrochloric acid to produce 1 mole of zinc chloride and 1 mole of hydrogen gas.

Identifying the Limiting Reactant

To identify the limiting reactant, we need to compare the mole ratio of the reactants with the mole ratio required by the chemical equation. In this case, we have 6.0 moles of zinc and 6.0 moles of hydrochloric acid. The mole ratio of zinc to hydrochloric acid required by the equation is 1:2.

Calculating the Mole Ratio

To calculate the mole ratio, we can divide the number of moles of each reactant by the smallest number of moles. In this case, the smallest number of moles is 6.0 moles (either zinc or hydrochloric acid). Therefore, the mole ratio of zinc to hydrochloric acid is:

Zn: HCl = 6.0 moles / 6.0 moles : 6.0 moles / 6.0 moles = 1:1

Comparing the Mole Ratio

The calculated mole ratio of 1:1 is different from the required mole ratio of 1:2. This means that the actual mole ratio of zinc to hydrochloric acid is not sufficient to produce the required amount of product.

Determining the Limiting Reactant

Since the actual mole ratio of zinc to hydrochloric acid is 1:1, and the required mole ratio is 1:2, we can conclude that hydrochloric acid is the limiting reactant. This is because hydrochloric acid is present in a smaller amount than required by the equation, and it will be completely consumed before zinc is fully reacted.

Conclusion

In conclusion, the limiting reactant in the given chemical equation is hydrochloric acid (HCl). This is because the actual mole ratio of zinc to hydrochloric acid is 1:1, which is different from the required mole ratio of 1:2. The limiting reactant determines the amount of product formed, and in this case, hydrochloric acid is the limiting reactant.

Frequently Asked Questions

What is a limiting reactant? A limiting reactant is the reactant that determines the amount of product formed in a chemical reaction.
How do you identify the limiting reactant? To identify the limiting reactant, you need to compare the mole ratio of the reactants with the mole ratio required by the chemical equation.
What is the role of the limiting reactant in a chemical reaction? The limiting reactant determines the amount of product formed in a chemical reaction.

Key Takeaways

The limiting reactant determines the amount of product formed in a chemical reaction.
To identify the limiting reactant, you need to compare the mole ratio of the reactants with the mole ratio required by the chemical equation.
The limiting reactant is the reactant that is present in a smaller amount than required by the equation.

References

Chemistry: An Atoms First Approach, by Steven S. Zumdahl
General Chemistry: Principles and Modern Applications, by Linus Pauling

Glossary

Limiting reactant: The reactant that determines the amount of product formed in a chemical reaction.
Mole ratio: The ratio of the number of moles of each reactant to the number of moles of each product.
Chemical equation: A representation of a chemical reaction in the form of a balanced equation.

Introduction

Chemical reactions are an essential part of chemistry, and understanding them is crucial for various fields, including science, engineering, and medicine. In our previous article, we discussed the concept of limiting reactants and how to identify them using the given chemical equation. In this article, we will provide a Q&A section to help you better understand the topic.

Q&A

Q1: What is a limiting reactant?

A1: A limiting reactant is the reactant that determines the amount of product formed in a chemical reaction.

Q2: How do you identify the limiting reactant?

A2: To identify the limiting reactant, you need to compare the mole ratio of the reactants with the mole ratio required by the chemical equation.

Q3: What is the role of the limiting reactant in a chemical reaction?

A3: The limiting reactant determines the amount of product formed in a chemical reaction.

Q4: What is the difference between a limiting reactant and an excess reactant?

A4: A limiting reactant is the reactant that determines the amount of product formed, while an excess reactant is the reactant that is present in excess of the amount required by the equation.

Q5: How do you calculate the mole ratio of reactants?

A5: To calculate the mole ratio, you can divide the number of moles of each reactant by the smallest number of moles.

Q6: What is the significance of the mole ratio in a chemical reaction?

A6: The mole ratio is essential in determining the limiting reactant and the amount of product formed in a chemical reaction.

Q7: Can a chemical reaction have multiple limiting reactants?

A7: No, a chemical reaction can only have one limiting reactant.

Q8: How do you determine the limiting reactant in a complex chemical reaction?

A8: To determine the limiting reactant in a complex chemical reaction, you need to break down the reaction into simpler steps and identify the limiting reactant in each step.

Q9: What is the relationship between the limiting reactant and the yield of a chemical reaction?

A9: The limiting reactant determines the yield of a chemical reaction.

Q10: Can the limiting reactant be changed in a chemical reaction?

A10: No, the limiting reactant cannot be changed in a chemical reaction.