The melting point of a substance is the temperature at which a solid, ordered crystalline substance is in equilibrium with a more random liquid state, thereby undergoing a phase change.
Since the components of the solid substances are bound by strong intermolecular attractive forces, it also reflects the energy needed to weaken these attractive forces and move freely in the liquid state.
| Physical Properties | Chemical Properties |
|---|---|---|
Meaning | Physical properties are those properties that can be observed or measured without changing the substances' identity; that is, there is no change in the substance's chemical structure. It does not undergo any chemical reaction that results in a structural transformation, and no new substance is formed. |
| Extensive | Intensive |
|---|---|---|
Definition | The properties that change when the size or amount of the sample changes are defined as extensive properties. That is, if the properties are dependent on the amount of matter, then doubling the quantity of matter must also double the property. |
| Qualitative Analysis | Quantitative analysis |
|---|---|---|
Aim | Identifies what compounds or functional groups are present. Therefore, the type of information obtained is descriptive. For example, whether the compound changed color, evolved gas, or formed a precipitate.
| Measures how much of a compound is present and, therefore, numerically describes its quantity. |
Learning Objective: To study how to determine by qualitative analysis the physical properties of the state, nature, odor, color, solubility, and physical constants of an unknown organic compound.
Skill Level - Intermediate
Prerequisites:
Learning Objective: To study how molecular weight, molecular shape, functional group, and carbon number impact density.
Skill Level - Intermediate
Prerequisites:
Common names of alkanes
Learning Objective: To study which intermolecular forces and structural features affect the solubility of organic compounds in water.
Skill Level - Intermediate
Prerequisites:
Hydrophobicity
Learning Objective: To investigate which intermolecular forces are predominant in a liquid state and to study the impact of molecular weight, molecular shape, and polarity on the boiling point of liquids.
Skill Level - Intermediate
Prerequisites:
Learning Objective: To study the impact of symmetry, carbon numbers, geometry, and polarity on the melting point of solids.
Skill Level - Intermediate
Prerequisites:
Learning Objective: To learn about the intermolecular forces and how they impact an organic compound's physical properties.
Skill Level - Intermediate
Prerequisites:
Physical properties identify the substance's unique nature by subjecting the substance to qualitative and quantitative measurements. In these experiments, the substance does not undergo destruction or reconstitution of its composition but can change states/phases.