The Reaction between Hydrogen and Bromine

Oct 13, 2025 by ludoplayers7.com 80 views

Introduction

Hydrogen is a highly reactive gas that can react with various elements to form different compounds. One such reaction is the combination of hydrogen with bromine to produce hydrogen bromide gas. This reaction is an important example of a chemical reaction that involves the formation of a new compound through the combination of two elements. In this article, we will discuss the reaction between hydrogen and bromine, the standard enthalpies of formation of the reactants and products, and the implications of this reaction in chemistry.

The Reaction between Hydrogen and Bromine

The reaction between hydrogen and bromine is a simple combination reaction that can be represented by the following equation:

${H_2(g) + Br_2(g) \rightarrow 2 HBr(g)}$

In this reaction, one molecule of hydrogen gas reacts with one molecule of bromine gas to produce two molecules of hydrogen bromide gas. This reaction is a classic example of a combination reaction, where two elements combine to form a new compound.

Standard Enthalpies of Formation

The standard enthalpy of formation is a measure of the energy change that occurs when one mole of a compound is formed from its constituent elements in their standard states. The standard enthalpy of formation is denoted by the symbol ΔHf and is typically expressed in units of kJ/mol.

The standard enthalpies of formation of the reactants and products in the reaction between hydrogen and bromine are as follows:

Hydrogen (H2): The standard enthalpy of formation of hydrogen gas is zero, since it is an element in its standard state.
Bromine (Br2): The standard enthalpy of formation of bromine gas is 31.89 kJ/mol.
Hydrogen Bromide (HBr): The standard enthalpy of formation of hydrogen bromide gas is -36.40 kJ/mol.

Calculating the Standard Enthalpy of Reaction

The standard enthalpy of reaction is a measure of the energy change that occurs when a chemical reaction takes place under standard conditions. The standard enthalpy of reaction is denoted by the symbol ΔHrxn and is typically expressed in units of kJ/mol.

To calculate the standard enthalpy of reaction for the reaction between hydrogen and bromine, we can use the following equation:

ΔHrxn = Σ(ΔHf(products)) - Σ(ΔHf(reactants))

where ΔHf(products) is the standard enthalpy of formation of the products and ΔHf(reactants) is the standard enthalpy of formation of the reactants.

Substituting the values of the standard enthalpies of formation of the reactants and products, we get:

ΔHrxn = 2(-36.40 kJ/mol) - (0 kJ/mol + 31.89 kJ/mol) ΔHrxn = -72.80 kJ/mol - 31.89 kJ/mol ΔHrxn = -104.69 kJ/mol

Implications of the Reaction

The reaction between hydrogen and bromine has several implications in chemistry. Some of the key implications are as follows:

Energy Change: The reaction between hydrogen and bromine is an exothermic reaction, meaning that it releases energy in the form of heat. This is evident from the negative value of the standard enthalpy of reaction.
Formation of Hydrogen Bromide: The reaction between hydrogen and bromine produces hydrogen bromide gas, which is a highly reactive compound. Hydrogen bromide is used as a reagent in various chemical reactions, including the synthesis of other compounds.
Understanding Chemical Reactions: The reaction between hydrogen and bromine is a simple example of a chemical reaction that involves the formation of a new compound through the combination of two elements. Understanding this reaction can help us understand more complex chemical reactions and their underlying mechanisms.

Conclusion

Introduction

In our previous article, we discussed the reaction between hydrogen and bromine, the standard enthalpies of formation of the reactants and products, and the implications of this reaction in chemistry. In this article, we will answer some frequently asked questions about the reaction between hydrogen and bromine.

Q&A

Q: What is the reaction between hydrogen and bromine?

A: The reaction between hydrogen and bromine is a simple combination reaction that can be represented by the following equation:

${H_2(g) + Br_2(g) \rightarrow 2 HBr(g)}$

In this reaction, one molecule of hydrogen gas reacts with one molecule of bromine gas to produce two molecules of hydrogen bromide gas.

Q: What is the standard enthalpy of formation of hydrogen bromide?

A: The standard enthalpy of formation of hydrogen bromide gas is -36.40 kJ/mol.

Q: Is the reaction between hydrogen and bromine exothermic or endothermic?

A: The reaction between hydrogen and bromine is exothermic, meaning that it releases energy in the form of heat. This is evident from the negative value of the standard enthalpy of reaction.

Q: What is the standard enthalpy of reaction for the reaction between hydrogen and bromine?

A: The standard enthalpy of reaction for the reaction between hydrogen and bromine is -104.69 kJ/mol.

Q: What are the implications of the reaction between hydrogen and bromine in chemistry?

A: The reaction between hydrogen and bromine has several implications in chemistry, including the formation of hydrogen bromide gas, which is a highly reactive compound. Hydrogen bromide is used as a reagent in various chemical reactions, including the synthesis of other compounds.

Q: Can you provide an example of a real-world application of the reaction between hydrogen and bromine?

A: Yes, one example of a real-world application of the reaction between hydrogen and bromide is in the production of hydrobromic acid, which is used as a reagent in various chemical reactions.

Q: What are some common mistakes to avoid when working with hydrogen bromide?

A: Some common mistakes to avoid when working with hydrogen bromide include:

Handling hydrogen bromide gas in an open container, as it can react with moisture in the air to form hydrobromic acid.
Not wearing protective gear, including gloves and goggles, when handling hydrogen bromide.
Not following proper safety protocols when handling hydrogen bromide, including using a fume hood and following proper disposal procedures.

Conclusion

In conclusion, the reaction between hydrogen and bromine is a simple combination reaction that produces hydrogen bromide gas. Understanding this reaction can help us understand more complex chemical reactions and their underlying mechanisms. We hope that this Q&A article has provided you with a better understanding of the reaction between hydrogen and bromine and its implications in chemistry.