Question

What do the coefficients of a balanced chemical equation tell us about the proportions in which atoms and molecules react on an individual (microscopic) basis?

Short answer

The coefficients in a balanced chemical equation indicate the proportions in which atoms and molecules react on a microscopic basis. They show how the reactants combine in specific ratios to form the products, and these ratios remain constant whether we consider individual molecules or moles of the substances involved in the reaction.

Step-by-step solution

Understanding a balanced chemical equation

A balanced chemical equation is a representation of a chemical reaction where 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. This follows the Law of Conservation of Matter, which states that matter cannot be created or destroyed in a chemical reaction.

Interpreting coefficients

In a balanced chemical equation, the numbers in front of the chemical formulas (called coefficients) represent the number of molecules (or moles) that participate in the reaction. For example, in the equation: \(2H_2 + O_2 \rightarrow 2H_2O\) The coefficients are 2 for \(H_2\), 1 for \(O_2\), and 2 for \(H_2O\). These coefficients show that 2 molecules of hydrogen gas react with 1 molecule of oxygen gas to produce 2 molecules of water.

Proportions of atoms and molecules at a microscopic level

The coefficients in a balanced chemical equation give us the proportions of atoms and molecules involved in the reaction at a microscopic level. In the example above, we see that 2 hydrogen molecules react with 1 oxygen molecule to form 2 water molecules. This means that the ratio of hydrogen to oxygen molecules is 2:1, and the ratio of hydrogen to water molecules is also 2:1. In other words, the coefficients tell us the ratio in which the reactants combine to form the products.

Coefficients can also apply to moles

The coefficients in a balanced chemical equation can also be interpreted as the number of moles of each substance. One mole of a substance contains Avogadro's number (\(6.022 \times 10^{23}\)) of particles (atoms, ions, molecules, etc.). In this context, instead of counting individual molecules, we count moles. For example: \(2 \, moles \, H_2 + 1 \, mole \, O_2 \rightarrow 2 \, moles \, H_2O\) This means that the ratio of moles of hydrogen to moles of oxygen is still 2:1, and the ratio of moles of hydrogen to moles of water is also 2:1. In conclusion, the coefficients in a balanced chemical equation indicate the proportions in which atoms and molecules react on a microscopic basis. They show how the reactants combine in specific ratios to form the products, and these ratios remain constant whether we consider individual molecules or moles of the substances involved in the reaction.