Question

Write a chemical equation representing the decomposition of water into two gaseous products. What are the products?

Short answer

The balanced chemical equation representing the decomposition of water into its gaseous products is: \( 2 H_{2}O \rightarrow 2 H_{2} + O_{2} \) The gaseous products are hydrogen gas (H₂) and oxygen gas (O₂).

Step-by-step solution

Identify the reactants and products

Water is composed of hydrogen and oxygen, and its chemical formula is H₂O. When water decomposes, it breaks down into its constituent elements, which are hydrogen and oxygen. Both of these elements exist as diatomic molecules in their gaseous form (H₂ and O₂). Hence, the gaseous products of water decomposition are hydrogen (H₂) and oxygen (O₂).

Write the unbalanced chemical equation

In the unbalanced equation, we write the reactants on the left side and the products on the right side of the arrow (→). Based on the information in step 1, we can write the unbalanced chemical equation as: H₂O → H₂ + O₂

Balance the chemical equation

Now, we need to balance the chemical equation to ensure that the number of atoms of each element is equal on both sides of the equation. In the unbalanced equation, we have 2 hydrogen atoms and 1 oxygen atom in the reactant (water), while we have 2 hydrogen atoms and 2 oxygen atoms in the products (hydrogen and oxygen gas). To balance the equation, we can place a coefficient (2) in front of the water molecule: 2 H₂O → H₂ + O₂ Now we have 4 hydrogen atoms and 2 oxygen atoms on the left side of the equation. To balance the hydrogen atoms, place a coefficient (2) in front of the hydrogen gas molecule: 2 H₂O → 2 H₂ + O₂ Now the chemical equation is balanced, with 4 hydrogen atoms and 2 oxygen atoms on both sides.

Final Balanced Chemical Equation

The balanced chemical equation representing the decomposition of water into its gaseous products is: 2 H₂O → 2 H₂ + O₂ The gaseous products of this decomposition reaction are hydrogen gas (H₂) and oxygen gas (O₂).

Key concepts

Chemical Equations

Chemical equations play a crucial role in conveying the specifics of chemical reactions. They are symbolic representations showing the reactants that start a reaction and the products formed as a result.
For instance, consider the decomposition of water. The reactants in this process are water molecules (H_2O), and the products are hydrogen (H_2) and oxygen gases (O_2). The chemical equation serves as a recipe, indicating that when water molecules are subjected to a decomposition reaction, they yield hydrogen and oxygen gases. The symbols (→) in the equation are akin to saying 'produces' or 'yields', providing a clear direction of the reaction.

Balancing Chemical Equations

When it comes to chemical equations, it's not enough to simply list the reactants and products. The equation must adhere to the law of conservation of mass, which states that in a closed system, mass is neither created nor destroyed.
Balancing a chemical equation ensures that the number of atoms for each element is the same on both sides of the equation. In the decomposition of water, we balance the equation by adjusting coefficients—these are numbers placed in front of compounds or elements within a chemical equation. For instance, we started with 2 H_2O → H_2 + O_2, which indicated twice as many water molecules as required. By adding a coefficient of 2 in front of the hydrogen gas, 2 H_2O → 2 H_2 + O_2, we achieve a balance, making sure there are four hydrogen atoms and two oxygen atoms present on both sides of the equation. This process of balancing is a fundamental skill in chemistry that ensures our equations accurately reflect reality.

Decomposition Reactions

Decomposition reactions are a type of chemical reaction where a single compound breaks down into two or more simpler substances. These reactions can be initiated by various factors such as heat, light, or electricity.
In the case of water's decomposition, the reaction is typically carried out by electrolysis, requiring an electrical current to break the chemical bonds. The water molecule, initially stable, splits into hydrogen and oxygen gases. This is reflected in the balanced chemical equation we previously derived: 2 H_2O → 2 H_2 + O_2. Understanding decomposition reactions helps us comprehend the chemical processes behind materials breaking down, which is an important concept in both natural processes and industrial applications.