Abnormal Molar Masses – Class 12 | Chapter – 2 | Chemistry Short Notes Series PDF for NEET & JEE

Abnormal Molar Masses: Abnormal molar masses are observed in certain cases where the measured molar mass of a substance is different from its expected molar mass based on its chemical formula. This can occur due to various reasons such as association or dissociation of molecules, ionization of particles, and hydration or solvation of molecules.

Examples of Abnormal Molar Masses

Some examples of abnormal molar masses include:

  • Association: In some cases, molecules of a substance can associate to form larger molecules or aggregates. For example, acetic acid molecules can associate to form dimers, which can lead to a higher measured molar mass than expected.
  • Dissociation: Conversely, some substances may dissociate into smaller particles, such as ions, when dissolved in a solvent. For example, sodium chloride dissociates into sodium and chloride ions when dissolved in water, leading to a lower measured molar mass than expected.
  • Ionization: Some substances may also ionize in solution, forming charged particles that can affect the measured molar mass. For example, when hydrochloric acid dissolves in water, it ionizes to form hydrogen ions and chloride ions.
  • Hydration or solvation: Finally, some substances may be hydrated or solvated in solution, meaning that water or another solvent is incorporated into the structure of the substance. This can affect the measured molar mass by adding additional mass due to the water or solvent molecules. For example, when copper sulfate dissolves in water, it forms hydrated copper ions that contribute to the measured molar mass.

Biology Quiz & Notes Physics Quiz & Notes Chemistry Quiz & Notes

Follow on Facebook

By Team Learning Mantras