Chemistry Class: Physical and Chemical Changes

Questions and Answers

What characterizes a physical change?

It creates a new substance with a different identity.

It is accompanied by a chemical reaction.

It involves energy release in all scenarios.

It includes changes in phase, mass, and temperature. (correct)

Which of the following best describes an endothermic reaction?

It absorbs energy or heat from the surroundings. (correct)

It occurs only in the presence of water.

It results in rust formation.

It releases energy to the surroundings.

Which is an example of an exothermic reaction?

Burning of sugar. (correct)

Melting ice.

Evaporating liquids.

Photosynthesis.

Which of the following is an intensive physical property?

Density Signup and view all the answers

What does the Law of Conservation of Mass state?

Total mass remains constant during changes. Signup and view all the answers

What defines extensive physical properties?

Dependent on the amount of substance Signup and view all the answers

Combustibility is an example of which type of property?

Chemical property Signup and view all the answers

Which process is an example of a physical change?

Melting ice. Signup and view all the answers

Which statement accurately differentiates extensive properties from intensive properties?

Extensive properties change when the substance is divided. Signup and view all the answers

What is the effect of a physical change on the substance?

The substance remains unchanged Signup and view all the answers

What is a common feature of chemical changes?

Changes result in a substance with a different identity. Signup and view all the answers

Which of the following describes a chemical change?

The rusting of iron Signup and view all the answers

Which reaction typically occurs without releasing heat?

Rusting of iron. Signup and view all the answers

Which term describes the tendency of a body to remain at rest?

Inertia Signup and view all the answers

What is the relationship between mass and inertia?

Inertia is proportional to mass Signup and view all the answers

What occurs during an endothermic reaction?

Heat is absorbed Signup and view all the answers

Which property of matter depends on the amount of substance present?

Mass Signup and view all the answers

Which of the following describes a physical change?

Ice melting into water Signup and view all the answers

What type of property can only be observed during a chemical reaction?

Reactivity Signup and view all the answers

Which of the following is an example of an endothermic reaction?

Photosynthesis in plants Signup and view all the answers

Which property remains the same regardless of the amount of matter present?

Color Signup and view all the answers

Which process describes an exothermic reaction?

Burning wood Signup and view all the answers

In which state of matter are particles closely packed and unable to move freely?

Solid Signup and view all the answers

The change in energy during which type of reaction results in a temperature decrease in the surroundings?

Endothermic Signup and view all the answers

Study Notes

Properties of Matter

Flammability, Toxicity, Acidity, Reactivity: Key chemical properties that determine how substances behave.
Heat of Combustion: The amount of energy released during combustion.

Changes in Matter

Physical Change: Involves alterations in form, not chemical identity (e.g., phase, size, volume, temperature).
Chemical Change: Original material transforms into a different substance with a new identity. Results from chemical reactions and involves energy changes:
- Endothermic Reaction: Absorbs energy (e.g., photosynthesis, melting ice).
- Exothermic Reaction: Releases energy (e.g., rusting of iron, burning of sugar).

Energy Changes

Freezing water releases heat, making it an exothermic reaction. Supercooling can trap heat within the environment.

Law of Conservation of Mass

Mass remains unchanged during physical and chemical changes. Matter is neither created nor destroyed.

Physical Properties of Matter

Intensive Properties: Independent of the amount (e.g., density, color, boiling point).
Extensive Properties: Dependent on the amount (e.g., mass, volume, heat content).

Common Properties of Matter

Mass: Quantity of matter present.
Inertia: Resistance to changes in motion; relates to mass.
Weight: Gravitational force exerted on a body.
Volume: Space occupied by matter.
Density: Mass per unit volume of an object.
Impenetrability: No two objects can occupy the same space simultaneously.

Chemical Properties of Matter

Observable during chemical reactions (e.g., combustibility, oxidation).
Changes in chemical identity and internal structure occur during chemical reactions.

Matter

Defined as anything with mass and occupying space; composed of atoms.
Exists in various states: solid, liquid, gas, plasma, influenced by temperature and pressure.
Comprised of celestial bodies and living organisms, impacting the universe through various forces.

Classification of Matter

By Origin:
- Inorganic Matter: From non-living things.
- Organic Matter: From living things.
By State:
- Solid: Rigid structure with fixed particles, definite shape and volume.
- Liquid: Definite volume but no specific shape; particles can move relative to each other.

Importance of Chemistry

Fundamental science that explores properties, structures, and interactions of matter, including energy changes.

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Description

Explore the concepts of physical and chemical changes in chemistry through this engaging quiz. Understand the distinctions between these changes alongside related properties such as flammability and reactivity. Test your knowledge on how these transformations impact matter and energy.