Question

Create a chart that compares physical and chemical properties. Give two examples for each type of property

Answer 1

Physical properties, such as melting point and density, define a substance without altering its composition. Water's melting point (0°C) and gold's density (19.32 g/cm³) exemplify these traits. In contrast, chemical properties, like flammability and reactivity with acid, showcase a substance's tendency to undergo specific reactions, as seen in gasoline's combustibility and sodium's reaction with hydrochloric acid.

Physical Properties:

1. Melting Point:

- Physical Definition: The temperature at which a substance changes from a solid to a liquid state.

- Example 1: Water has a melting point of 0 degrees Celsius.

- Example 2: Iron has a melting point of 1,538 degrees Celsius.

2. Density:

- Physical Definition: Mass per unit volume of a substance.

- Example 1: The density of gold is about 19.32 grams per cubic centimeter.

- Example 2: Helium is much less dense than air.

Chemical Properties:

1. Flammability:

- Chemical Definition: The ability of a substance to burn or support combustion.

- Example 1: Gasoline is highly flammable.

- Example 2: Hydrogen is a flammable gas.

2. Reactivity with Acid:

- Chemical Definition: The tendency of a substance to undergo chemical reactions with acids.

- Example 1: Sodium reacts vigorously with hydrochloric acid.

- Example 2: Calcium carbonate reacts with dilute hydrochloric acid to produce carbon dioxide.

Answer 2

Chemical properties:

Those properties which change the chemical nature of matter.

Example:

• Heat of combustion
• Enthalpy of formation

Physical properties:

Those properties which do not change the chemical nature of matter.

Example

• B.P
• M.P
• F.P

Differences between chemical and physical properties:

Chemical properties Physical properties

1. Observed after the change bringing 1. Observed with out being

the change change

2. These changes the molecules 2. only change physical state

3. Chemical identity changes 3.Chemical identity not changes

4. Structure of material changes 4.Structure of material not change

5. Chemical reaction is needed 5. No need of Chemical reaction

6. depend on composition 6. Does not depend on composition