Question

Define physical and chemical properties, provide provide three examples of each discuss their rversibility and expain the fundamental differences between them

Answer 1

Physical properties are characteristics that describe matter without changing its identity, while chemical properties describe how matter changes its chemical structure or composition. Examples of physical properties include color, boiling point, and density. Examples of chemical properties include flammability, reactivity, and toxicity. Physical properties are generally reversible, while chemical properties often involve irreversible chemical changes.

Step-by-step explanation:

Physical properties are characteristics that describe matter without changing its identity. Examples include size, shape, color, and mass. Physical properties can be observed or measured without causing a chemical change. Chemical properties, on the other hand, describe how matter changes its chemical structure or composition. Examples of chemical properties include flammability and reactivity. The observation of chemical properties involves a chemical change in the matter, resulting in matter with a different identity and different physical and chemical properties.

Physical properties:

1. Color: The color of an object is a physical property that can be observed without altering the object's identity. For example, a red apple will still be red even if it is cut into smaller pieces.
2. Boiling point: The boiling point of a substance is the temperature at which it changes from a liquid to a gas. This is a physical property because it can be measured without altering the substance's chemical composition. For example, the boiling point of water is 100 degrees Celsius.
3. Density: Density is a measure of how much mass is contained in a given volume. It is a physical property because it can be measured without causing a chemical change. For example, the density of lead is higher than the density of aluminum.

Chemical properties:

1. Flammability: Flammability is the ability of a substance to burn. When a substance burns, it undergoes a chemical change and forms new substances. For example, wood is flammable because it can burn and produce ash and smoke.
2. Reactivity: Reactivity is the ability of a substance to undergo a chemical reaction with another substance. This can result in the formation of new substances. For example, sodium is highly reactive and can react violently with water, producing hydrogen gas and sodium hydroxide.
3. Toxicity: Toxicity is a chemical property that describes the ability of a substance to cause harm to living organisms. Certain chemicals can be toxic and cause adverse effects on human health. For example, mercury is highly toxic and can cause damage to the nervous system.

Physical properties are generally reversible, meaning they can be changed back to their original state without permanently altering the substance. For example, if you melt an ice cube, you can freeze the water again to convert it back into ice. Chemical properties, on the other hand, involve chemical changes that are often irreversible. Once a chemical change occurs, it is difficult or impossible to reverse it and restore the original substance.

The fundamental difference between physical and chemical properties lies in whether a change in the property results in a change in the chemical identity of the substance. Physical properties can be observed or measured without causing a change in the substance's chemical composition, while chemical properties involve changes in the chemical structure or composition of the substance.