Introduction of Chemical Properties
Chemical properties are descriptions of the ability of a substance to undergo physical and chemical changes under certain conditions. A variety of chemical properties can be used to characterize and classify different types of substances. These properties are determined by the molecular structure of the substance and its reactivity with other substances.
Common chemical properties include flammability, reactivity, acidity, and volatility. Flammability refers to the ability of a substance to ignite and radiate energy when exposed to heat or a flame. Reactivity is a measure of the rate of reaction that occurs when a substance is exposed to other substances. Acidity refers to how much hydrogen ions a substance is able to donate and accept from solutions. Volatility describes how easily a substance will evaporate at a given temperature and pressure.
The reactivity of a substance often determines its flammability. The molecular structure of a substance greatly affects its reactivity, particularly its ability to bond with other molecules. Some molecules are more prone to reacting than others due to their relatively weak bonds. This makes them more prone to oxidation and combustion, make them more flammable.
Other properties related to reactivity are oxygen-affinity and thermodynamic stability. Oxygen affinity describes the ability of a molecule to accept oxygen atoms. Molecules with higher oxygen-affinity are generally more reactive and less stable. Conversely, molecules with lower oxygen-affinity tend to be more stable.
The boiling point of a substance is another chemical property often used to characterize a substance. This property determines the temperature at which a liquid will begin to evaporate. Generally, substances with higher boiling points require more energy to vaporize. This property is commonly used to classify substances as volatile (low boiling point) or non-volatile (high boiling point).
The vapor pressure of a substance is another common chemical property. Vapor pressure is the amount of pressure exerted by a vapor on the walls of its container. Volatile substances have higher vapor pressures because they have lower boiling points, while non-volatile substances have lower vapor pressures.
The ability of a substance to form a solution (solubility) is another important chemical property. The solubility of a substance determines how easily it can dissolve in a solvent. Generally, polar molecules are more soluble in polar solvents and non-polar molecules are more soluble in non-polar solvents.
The electrical conductivity of a substance is a measure of the ability of the molecules to conduct electric current. Generally, molecules in ionic form are more conductive than molecules in non-ionic form.
The pH of a substance is another useful chemical property. pH is a measure of the acidity or alkalinity of a solution. A pH of 7 is neutral, anything above 7 is an alkaline solution and anyting below 7 is an acidic solution.
In conclusion, chemical properties are important characteristics that can be used to characterize and classify substances. These properties are related to the molecular structure, reactivity, volatility, solubility, electrical conductivity and the acidity or alkalinity of the substance.
