Question

Balance this equation and classify it as combination, decomposition, single- replacement, or. double-replacement: \(\mathrm{H}_{2} \mathrm{O}_{2} \rightarrow \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2}\)

Short answer

The balanced equation is \(\mathrm{H}_{2} \mathrm{O}_{2} \rightarrow 2 \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2}\), and the reaction type is decomposition.

Step-by-step solution

Identify the reactants and products

In the given equation, hydrogen peroxide (\(\mathrm{H}_{2} \mathrm{O}_{2}\)) is the reactant, and water (\(\mathrm{H}_{2} \mathrm{O}\)) and oxygen gas (\(\mathrm{O}_{2}\)) are the products. The unbalanced equation is: \(\mathrm{H}_{2} \mathrm{O}_{2} \rightarrow \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2}\)

Balance the equation

To balance the equation, we need to make sure that the number of atoms of each element on the reactant side is equal to the number of atoms of the same element on the product side. 1. There are 2 hydrogen atoms in the reactant and 2 hydrogen atoms in the product, so hydrogen atoms are already balanced. 2. There are 2 oxygen atoms in the reactant, 1 in the water molecule, and 2 in the oxygen gas molecule. To balance the equation, add a coefficient of 2 in front of the water molecule: \(\mathrm{H}_{2} \mathrm{O}_{2} \rightarrow 2 \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2}\) Now, the equation is balanced with 2 hydrogen atoms and 4 oxygen atoms on each side.

Classify the reaction type

Now that the equation is balanced, let's identify the type of reaction. We have the following general definitions for each type: 1. Combination: Two or more reactants combine to form a single product. 2. Decomposition: A single reactant breaks down into two or more simpler products. 3. Single-replacement: One element replaces another element in a compound to form a new compound and a new element. 4. Double-replacement: Two compounds exchange positive ions to form two new compounds. In our case, a single reactant (\(\mathrm{H}_{2} \mathrm{O}_{2}\)) breaks down into two simpler products (\(\mathrm{H}_{2} \mathrm{O}\) and \(\mathrm{O}_{2}\)). Therefore, this is a decomposition reaction. So, the final balanced equation and reaction type are: \(\mathrm{H}_{2} \mathrm{O}_{2} \rightarrow 2 \mathrm{H}_{2} \mathrm{O}+\mathrm{O}_{2}\) Type: Decomposition

Key concepts

Decomposition Reaction

When learning about chemical reactions, understanding a decomposition reaction is essential. This type of reaction involves a single compound breaking down to form two or more simpler substances.

Think of decomposition as the opposite of a combination reaction. While a combination reaction has multiple reactants forming one product, in a decomposition reaction, you start with one and end up with more. A classic example is the decomposition of hydrogen peroxide (olinebreak olinebreak olinebreak olinebreak olinebreak olinebreakolinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreakolinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak)olinebreak, which breaks down into water (olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak) and oxygen gas (olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak olinebreak).

There are various instances where a decomposition reaction occurs, such as the electrolysis of water to form hydrogen and oxygen or the decomposition of organic material in composting. These reactions are important in both industrial processes and natural environmental cycles.

Chemical Reaction Classification

Chemistry is full of patterns and classifications, which help students predict and understand how different substances interact. Each chemical reaction falls into specific categories based on what occurs during the reaction.

The four primary types of chemical reactions are combination, decomposition, single-replacement, and double-replacement. As shown in the practice exercise, determining the type of reaction involves looking at the reactants and products to see how they change.

Combination Reactions

Compound formation from simpler reactants.

Decomposition Reactions

A single reactant breaks down into simpler substances, which we discussed in detail earlier.

Single-Replacement Reactions

One element takes the place of another in a compound.

Double-Replacement Reactions

Two compounds exchange components, resulting in two new compounds.

By being able to classify reactions, students can predict product formation and the energy changes that might occur during the reaction.

Stoichiometry

Stoichiometry might sound intimidating, but it's simply the math behind chemistry—think of it as the recipe for a chemical reaction. This part of chemistry involves calculating the amounts of reactants and products in a chemical reaction.

The core principle of stoichiometry is the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. Therefore, in a balanced chemical equation, the mass and the number of atoms of each element are the same on both sides of the reaction.

Stoichiometric Coefficients

The numbers placed in front of compounds in a reaction (like the '2' in front of olinebreak) are called stoichiometric coefficients. They indicate the proportions of reactants and products.

In the decomposition of hydrogen peroxide, stoichiometry helps us balance the equation to ensure that the number of atoms of each element is the same on both sides. This is crucial for experiments and industrial processes where the exact amounts of substances needed must be known.