In the equation shown, what are the reactants
The Correct Answer and Explanation is:
The correct answer is B. Hydrogen and oxygen molecules.
In the chemical equation:
2H2+O2→2H2O2H_2 + O_2 \rightarrow 2H_2O
the substances on the left side represent the reactants. These are the starting materials in a chemical reaction. In this case, the reactants are molecular hydrogen (H2H_2) and molecular oxygen (O2O_2). Each hydrogen molecule consists of two hydrogen atoms, and each oxygen molecule contains two oxygen atoms. Together, these molecules undergo a chemical transformation to produce water molecules on the right side of the equation, which are the products.
Option A, “hydrogen atoms,” is incorrect because hydrogen does not exist naturally as single atoms in standard conditions. Instead, it forms stable diatomic molecules (H2H_2) due to strong covalent bonding between the atoms. Similarly, option C, “water molecules,” is incorrect because water is the product formed as a result of the reaction, not a substance that participates as a reactant.
This distinction is central to understanding how chemical reactions operate. Reactants are the ingredients you begin with and products are the outcomes of the reaction. Identifying reactants requires looking at the substances present before the reaction arrow in the chemical equation. Once the reaction occurs, these reactants interact in specific proportions defined by the coefficients in the equation, producing new substances.
In the case of hydrogen and oxygen, the reaction is a classic example of a synthesis reaction, where two simpler substances combine to form a more complex compound. This specific reaction is also highly exothermic, meaning it releases energy in the form of heat and light, which is why hydrogen is used as a fuel in rockets and other high-energy systems.
Understanding which substances are reactants and which are products is essential for balancing equations and predicting the outcomes of chemical reactions.
