Property and Energy Changes in Chemical Reactions

Liquefied petroleum gas (LPG) is the gas we use in the kitchen. It is a liquid inside the cylinder. It turns into gas as it exits the cylinder (Change A), then it first burns (Change B). The following claims relate to these changes: Select the appropriate option.

• Process B is physical change.

• Process B is chemical change.

• Both processes A and B are chemical change.

• Both processes A and B are physical change.

• No change will happen to both processes.

When you mix two different substances together, sometimes a chemical reaction occurs that forms a new substance. Which statement best describes what happens during a chemical reaction when two different substances form a new substance?

• The atoms in the substances physically combine, but no new substance is formed.

• The atoms in the substances lose their individual properties, resulting in a mixture.

• The substances break down into simpler components without forming a new substance.

• The atoms of the substances rearrange to form new substance/s with different properties.

• The atoms substances undergo a change in state but maintain their original chemical composition.

How does the mass of the water molecules compare with the masses of H atoms and O atoms after a chemical reaction? Choose all that applies.

• The mass of the water molecules is less than the combined masses of H atoms and O atoms.

• The mass of water molecules is greater than the mass of a hydrogen atom or an oxygen atom.

• The mass of the water molecules is negligible compared to the masses of H atoms and O atoms.

• The mass of water molecules is equal to the total mass of four hydrogen and two oxygen atoms.

• The mass of the water molecules is inversely proportional to the combined masses of H atoms and O atoms.

Which of the following equations is balanced?

• A

• B

• C

• D

• E

Which of the following chemical equations is balanced?

• A

• B

• C

• D

• E

Which of the following chemical equations is balanced?

• A

• B

• C

• D

• E

Which of the following chemical equations is balanced?

• A

• B

• C

• D

• E

Choose the best term to complete the statement below:

Breaking bonds during a chemical reaction requires ________ energy.

• releasing

• multiplying

• converting

• adding

• none of the above

What type of energy is found in all states of matter?

• light and kinetic

• gravitational and sound

• electrical and light

• kinetic and potential

• potential and electrical

Choose the best term to complete the statement below:

Making new bonds during a chemical reaction requires ________ energy.

• releasing

• multiplying

• converting

• adding

• none of the above