Chemistry Regents Practice Test 2026 - Free Chemistry Regents Practice Questions and Study Guide

The primary purpose of a chemical formula is to convey the types and quantities of atoms in a compound. A chemical formula, such as H₂O for water or CO₂ for carbon dioxide, specifies the elements involved and the number of atoms of each element present in one molecule of the compound. This information is crucial for understanding the composition and behavior of substances in chemical reactions.

Knowing the types of atoms and their ratios helps chemists predict how substances will interact, and it provides foundational information for calculating molar masses and preparing solutions. Therefore, this understanding is integral to various applications in chemistry, including stoichiometry and reaction balancing.

In contrast, providing boiling points, indicating crystal arrangements, or specifying phases of matter, while important in their own contexts, do not capture the fundamental compositional information that a chemical formula provides.