Question

For the unbalanced chemical equation \(\mathrm{HCl}(g)+\mathrm{O}_{2}(g) \rightarrow \mathrm{H}_{2} \mathrm{O}(g)+\mathrm{Cl}_{2}(g)\) a. list the reactant(s). b. list the product(s).

Short answer

a. Reactants: \(\mathrm{HCl}(g)\) and \(\mathrm{O}_{2}(g)\) b. Products: \(\mathrm{H}_{2} \mathrm{O}(g)\) and \(\mathrm{Cl}_{2}(g)\)

Step-by-step solution

Identify the reactants

The reactants are the substances that participate in the chemical reaction. They are found on the left side of the arrow in the chemical equation. In this case, the reactants are hydrogen chloride (HCl) and oxygen (O₂). a. Reactants: \(\mathrm{HCl}(g)\) and \(\mathrm{O}_{2}(g)\)

Identify the products

The products are the substances that are formed as a result of the chemical reaction. They are found on the right side of the arrow in the chemical equation. In this case, the products are water (H₂O) and chlorine gas (Cl₂). b. Products: \(\mathrm{H}_{2} \mathrm{O}(g)\) and \(\mathrm{Cl}_{2}(g)\)

Key concepts

Reactants

In a chemical reaction, reactants are the starting materials that undergo change to form the products. They are typically located on the left side of a chemical equation. Understanding reactants is crucial in understanding how chemical reactions proceed.

• Reactants can be elements, compounds, or a combination of both.


• They participate actively in the reaction and transform into different substances during the process.


• An example is the chemical equation of a reaction between hydrogen chloride and oxygen: \(\mathrm{HCl}(g)+\mathrm{O}_{2}(g)\rightarrow ...\)

While studying a chemical equation, identifying the reactants helps in predicting the kinds of products that might form. It also sets the stage for balancing chemical equations. Keeping track of each reactant is important, as their quantities affect how much product is produced.

Products

Products are the substances that result from a chemical reaction. When reactants undergo changes through chemical processes, they form products. In any chemical equation, products are commonly indicated on the right side of the arrow.

• Products have different chemical properties and structures than the reactants.


• They signal the completion of a chemical reaction.


• In our example equation, water (\( \mathrm{H}_{2} \mathrm{O}(g)\)) and chlorine gas (\( \mathrm{Cl}_{2}(g) \)) are the products formed: \( ...\rightarrow \mathrm{H}_{2} \mathrm{O}(g)+\mathrm{Cl}_{2}(g) \).

Identifying the products is essential for understanding the outcome of a chemical reaction. Analyzing products also helps in investigating energy changes and matter transformations that occur during chemical processes.

Unbalanced Equations

An unbalanced equation is a chemical equation that does not have the same number of each type of atom on both sides of the reaction. Balancing these equations is necessary because it reflects the law of conservation of mass, which states that mass cannot be created or destroyed in a chemical reaction.

• Unbalanced equations are commonly encountered in initial stages of chemical analysis.


• The process involves adjusting coefficients to equalize the number of atoms for each element on both sides.


• From our example: \( \mathrm{HCl}(g)+\mathrm{O}_{2}(g)\rightarrow \mathrm{H}_{2} \mathrm{O}(g)+\mathrm{Cl}_{2}(g) \), as initially given, is unbalanced, needing adjustment to ensure mass conservation.

Balancing equations is a crucial skill in chemistry as it ensures equations accurately depict the real proportions in reactions. It aids in predicting reaction yields and in understanding the stoichiometry of the reactions.