Semester Exam Rev

Front

What is a physical change?

Back

A physical change is a change in which no new substances are formed. Examples include changes in state (like melting or freezing) and changes in appearance (like dissolving).

Front

What evidence indicates a physical change has occurred?

Back

Evidence of a physical change can include changes in state, temperature, or color without the formation of new substances.

Front

How many oxygen atoms are in the chemical formula Al₂(SO₄)₃?

Back

There are 12 oxygen atoms in Al₂(SO₄)₃.

Front

What happens to ice cream when it is left out at room temperature?

Back

The ice cream melts due to heat transfer from the warmer air to the colder ice cream.

Front

What is the effect of shaking a solution on the dissolving rate of a solute?

Back

Shaking a solution increases the dissolving rate by exposing the solute to the solvent more quickly.

Front

What is runoff in the context of watersheds?

Back

Runoff is the flow of water, often from rain or melting snow, that moves across the land and can carry pollutants into bodies of water.

Front

What is the role of temperature in the dissolving process?

Back

Higher temperatures generally increase the solubility of solids in liquids, allowing them to dissolve faster.

Front

What is the definition of a watershed?

Back

A watershed is an area of land where all the water that falls as precipitation drains into a common outlet, such as a river or ocean.

Front

What is the difference between a physical change and a chemical change?

Back

A physical change does not alter the chemical composition of a substance, while a chemical change results in the formation of new substances.

Front

What is the significance of observing color change in a solution?

Back

A color change can indicate a chemical reaction, but in some cases, it may also indicate a physical change, such as the dissolution of a colored solute.