Yes, it is possible for two compounds to have the same empirical formula but different molecular formulas. This occurs when the compounds are composed of the same elements in the same proportionate ratios, but the total number of atoms in each compound differs. For example, ethylene (C₂H₄) and benzene (C₆H₆) both have the same empirical formula, CH, as they consist of carbon and hydrogen in a 1:1 ratio. However, their molecular formulas are different due to the different numbers of atoms. Ethylene has two carbon and four hydrogen atoms, while benzene has six carbon and six hydrogen atoms. This phenomenon is particularly common in organic chemistry, where many different compounds can have the same ratios of elements.

The empirical formula is crucial in chemical analysis and synthesis as it provides fundamental information about the elemental composition of a compound. In analysis, it helps identify the basic proportions of elements in an unknown compound, facilitating its identification and characterisation. For instance, in combustion analysis, the empirical formula of a compound can be determined by measuring the amounts of carbon dioxide and water produced, giving insights into the compound's composition. In synthesis, understanding the empirical formula is key to predicting the outcomes of chemical reactions and designing pathways to create specific compounds. It enables chemists to calculate reactant quantities needed for a reaction, ensuring the efficient use of resources. Additionally, the empirical formula serves as a starting point for determining molecular structure in complex organic synthesis, guiding the synthesis process and helping in the development of new materials and pharmaceuticals.

In ionic compounds, the empirical formula represents the simplest ratio of the different ions that make up the compound. Unlike molecular compounds, where the formula can refer to actual molecules, the empirical formula for ionic compounds indicates the simplest integer ratio between the ions. For instance, sodium chloride (NaCl) consists of sodium ions (Na⁺) and chloride ions (Cl⁻) in a 1:1 ratio. However, this doesn't imply that there are individual NaCl molecules. In a crystal of sodium chloride, each sodium ion is surrounded by several chloride ions and vice versa. The empirical formula simplifies this complex 3D structure into the most basic ratio of ions, providing a fundamental understanding of the compound's composition without detailing its structure.

The empirical formula provides the simplest whole-number ratio of elements in a compound, not the exact number of atoms as in a molecular formula. It's a reduced form of the molecular formula. For example, glucose (C₆H₁₂O₆) and fructose (C₆H₁₂O₆) have the same molecular formula but different structures and properties. Their empirical formula, CH₂O, is identical, demonstrating that different compounds can share the same empirical formula. Therefore, while the empirical formula is crucial for understanding the basic composition of a compound, it cannot distinguish between compounds with the same ratios of atoms but different molecular structures. This limitation is significant in organic chemistry where isomers (compounds with the same molecular formula but different arrangements of atoms) are common.

The empirical formula can indeed be the same as the molecular formula, particularly when the compound's simplest ratio of elements matches its actual molecular composition. This situation typically occurs in two scenarios. Firstly, in small molecules where the number of atoms naturally occurs in the simplest ratio. For example, water (H₂O) and carbon dioxide (CO₂) have empirical formulas that are the same as their molecular formulas because their composition cannot be simplified further. Secondly, in larger molecules that happen to have a composition that does not simplify further. For instance, benzene (C₆H₆) has a molecular formula that is also its empirical formula. It is important to note that while the empirical formula can be the same as the molecular formula, it is not always so, especially in larger and more complex molecules.