Question

Write a balanced equation to show what occurs when hydrogen bromide dissolves and reacts with water. Include a hydronium ion in the equation.

Short answer

HBr + H₂O → H₃O⁺ + Br⁻

Step-by-step solution

- Write the Reactants

Start by writing the formula for the reactants. In this case, the reactants are hydrogen bromide (HBr) and water (H₂O).

- Identify Product Formation

When hydrogen bromide dissolves in water, it ionizes completely. This means it dissociates into its ions: hydrogen ion (H⁺) and bromide ion (Br⁻). The hydrogen ion (H⁺) then reacts with water to form a hydronium ion (H₃O⁺).

- Write the Intermediate Steps

The dissociation of HBr can be represented as follows: HBr → H⁺ + Br⁻ Then, the hydrogen ion reacts with water to form the hydronium ion: H⁺ + H₂O → H₃O⁺

- Combine the Steps into a Single Equation

Add the intermediate steps together to form the overall balanced chemical equation: HBr + H₂O → H₃O⁺ + Br⁻

Key concepts

hydrogen bromide

Hydrogen bromide, or HBr, is a diatomic molecule made up of hydrogen and bromine. It is a colorless gas at room temperature and is highly soluble in water, forming hydrobromic acid.
To understand how hydrogen bromide behaves in water, start by knowing that HBr is a strong acid. This means it fully dissociates into its ions when dissolved in water.
In the solution, hydrogen bromide breaks down into two ions: hydrogen ion (H⁺) and bromide ion (Br⁻). This process is crucial for further reactions that happen in the aqueous phase.

• HBr → H⁺ + Br⁻

ionization

Ionization refers to the process in which molecules split into ions. When hydrogen bromide dissolves in water, it undergoes ionization, breaking into hydrogen ions and bromide ions.
Because HBr is a strong acid, its ionization in water is complete. The step-by-step process involves HBr separating into H⁺ and Br⁻ ions. This separation is significant because these ions participate in further reactions.

• Ionization of HBr: HBr → H⁺ + Br⁻

This phenomenon is an important concept in chemistry as it explains how substances interact in an aqueous environment. Understanding ionization helps in predicting the behavior of acids, bases, and salts in water.

hydronium ion

The hydronium ion (H₃O⁺) is formed when a hydrogen ion (H⁺) from hydrogen bromide reacts with a water molecule (H₂O).
This happens because the hydrogen ion does not exist freely in water; it combines with a water molecule to create a more stable form, the hydronium ion. The reaction can be written as:

• H⁺ + H₂O → H₃O⁺

Seeing this in a balanced chemical equation:
HBr + H₂O → H₃O⁺ + Br⁻
The presence of hydronium ions in solution is a key indicator of acid strength, and these ions play a vital role in various chemical reactions.
This balance equation reflects the complete ionization of hydrogen bromide and its interaction with water to form the hydronium ion.

chemical reactions

Chemical reactions involve the transformation of reactants into products.
In our exercise, the reaction of hydrogen bromide (HBr) with water (H₂O) is a prime example.

Here’s a look at the overall process:

• HBr + H₂O → H₃O⁺ + Br⁻

The reactants are hydrogen bromide and water. The products of this reaction are hydronium ions and bromide ions.
Understanding the balanced chemical equation helps us see how the atoms rearrange, ensuring the mass and charge are conserved. This principle underpins the law of conservation in chemical reactions, making sure that the number of each type of atom stays the same before and after the reaction.