Question

Apply Hydrogen peroxide (H \(_{2} \mathrm{O}_{2} )\) decomposes to produce water and oxygen. Write a balanced chemical equation for this reaction, and determine the possible mole ratios.

Short answer

The balanced chemical equation for the decomposition of hydrogen peroxide (H\(_2\)O\(_2\)) into water and oxygen is: 2H\(_2\)O\(_2\) → 2H\(_2\)O + O\(_2\). The possible mole ratios are: H\(_2\)O\(_2\) to H\(_2\)O = 1:1, H\(_2\)O\(_2\) to O\(_2\) = 2:1, and H\(_2\)O to O\(_2\) = 2:1.

Step-by-step solution

Write the unbalanced chemical equation

The given reaction can be written as: H\(_2\)O\(_2\) → H\(_2\)O + O\(_2\)

Balance the chemical equation

To balance the equation, first count the number of atoms of each element on both sides of the equation. H: 2 on the left, 2 on the right O: 2 on the left, 3 on the right Since there are an odd number of oxygen atoms on the right side, multiply H\(_2\)O\(_2\) by 2 to create an even number of oxygen atoms: 2H\(_2\)O\(_2\) → H\(_2\)O + O\(_2\) Now there are 4 oxygen atoms on the left side and 3 on the right side. To balance the number of oxygen atoms, multiply H\(_2\)O by 2: 2H\(_2\)O\(_2\) → 2H\(_2\)O + O\(_2\) Now the equation is balanced, with 4 hydrogen atoms and 4 oxygen atoms on both sides.

Determine the mole ratios

The balanced chemical equation is: 2H\(_2\)O\(_2\) → 2H\(_2\)O + O\(_2\) Using the coefficients of the balanced equation, we can determine the mole ratios as follows: 1. Mole ratio of H\(_2\)O\(_2\) to H\(_2\)O: 2:2 (divide each coefficient by the smallest coefficient - in this case, they are both 2) Mole ratio of H\(_2\)O\(_2\) to H\(_2\)O = 1:1 2. Mole ratio of H\(_2\)O\(_2\) to O\(_2\): 2:1 Mole ratio of H\(_2\)O\(_2\) to O\(_2\) = 2:1 3. Mole ratio of H\(_2\)O to O\(_2\): 2:1 Mole ratio of H\(_2\)O to O\(_2\) = 2:1 In summary, the mole ratios are as follows: - H\(_2\)O\(_2\) to H\(_2\)O: 1:1 - H\(_2\)O\(_2\) to O\(_2\): 2:1 - H\(_2\)O to O\(_2\): 2:1

Key concepts

Stoichiometry

Stoichiometry is the branch of chemistry that deals with the quantitative relationships between the reactants and products in a chemical reaction. It is like a recipe for chemistry, telling you how much of each substance you need to react together to get a certain amount of product.

Imagine you are baking cookies, and your recipe needs 2 eggs for every cup of flour. Similarly, in chemistry, stoichiometry gives us the 'recipe' to understand how molecules interact with each other. It can predict how much reactants are required and how much products will be formed in a chemical reaction.

For instance, in the decomposition of hydrogen peroxide (\(H_2O_2\)), stoichiometry helps us calculate how much water (\(H_2O\)) and oxygen (\(O_2\)) will be produced from a specific amount of hydrogen peroxide. It involves understanding the mole concept, molar masses of elements and compounds, and the conservation of mass and atoms.

Using stoichiometry, you can also calculate other important details such as the concentration of solutions, gas volumes at different conditions, and the energy involved in reactions.

Mole Ratio

The mole ratio is a critical concept derived from the coefficients of a balanced chemical equation. It tells you the proportions of reactants and products involved in a chemical reaction. It's the heart of stoichiometry as it allows the calculation of how much of each substance is needed or produced. Think of it as the ratio of ingredients in a recipe – if you alter the ratio, you won't get the expected results (or cookies).

In the decomposition of hydrogen peroxide, for example, the balanced chemical equation is 2\(H_2O_2\rightarrow2H_2O + O_2\). From this, we can deduce the mole ratio between hydrogen peroxide and water is 1:1, meaning for each mole of hydrogen peroxide that decomposes, one mole of water is produced. Similarly, the mole ratio between hydrogen peroxide and oxygen is 2:1. Understanding these ratios is essential for calculating how much of each product is made from a given amount of reactant.

Additionally, mole ratios are not just theoretical. They have practical applications like determining the amount of a reagent to use in a reaction, or the volume of a gas produced at standard temperature and pressure.

Chemical Reaction

A chemical reaction is a process where reactant molecules interact to form new products. This can involve breaking bonds within reactants and forming new bonds to create the products. Chemical reactions are happening all around us, from the rusting of iron to the baking of bread, they are fundamental to understanding chemical processes.

To track and represent these changes, scientists use chemical equations, which are symbolic representations of chemical reactions. In such equations, reactants are shown on the left, products on the right, separated by an arrow signifying the direction of the reaction.

Balancing Chemical Equations

It is crucial for a chemical equation to be balanced, meaning that the same number of atoms of each element should be present on both sides of the equation. This reflects the law of conservation of mass, which states that matter can neither be created nor destroyed in a chemical reaction.

In the example of hydrogen peroxide decomposing, initially we start with an unbalanced equation with odd numbers of oxygen atoms. This was remedied by adjusting coefficients to ensure that all atoms balanced out, resulting in the equation 2\(H_2O_2\rightarrow2H_2O + O_2\) being balanced with equal numbers of hydrogens and oxygens on each side. These principles are key in helping students understand the fundamental processes of chemical changes in matter.