Chemical Changes and Dissolution Quiz

What happens to sugar molecules when they dissolve in water?

• They change into a new substance

• They break apart and spread throughout the water

• They float on top of the water

• They sink to the bottom permanently

Which of these is an example of a chemical reaction?

• Melting an ice cube

• Mixing oil and water

• Rusting of iron

• Breaking a glass

When salt dissolves faster in hot water than in cold water, this shows that:

• Chemical reactions are occurring

• Temperature affects dissolving rate

• Salt changes its chemical structure

• Water molecules are being destroyed

What is the best way to make sugar dissolve faster in water?

• Leave it still

• Add more sugar

• Add cold water

• Stir the mixture

Which observation indicates a chemical change has occurred?

• Change in temperature

• Formation of bubbles

• Change in shape

• Change in color and odor

What happens to the mass of a solution when a solid dissolves in it?

• The mass increases

• The mass stays the same

• The mass disappears

• The mass decreases

In a chemical reaction, what happens to the original substances?

• They remain unchanged

• They form new substances

• They simply mix together

• They evaporate completely

Which factor does NOT affect how quickly a solid dissolves?

• The color of the container

• Temperature of the liquid

• Amount of stirring

• Size of solid pieces

What is a precipitate?

• A solid that forms during a chemical reaction

• A type of liquid

• A form of gas

• A measurement tool

How can you tell if mixing two substances caused a chemical reaction?

• The mixture becomes cold

• The color becomes lighter

• A new substance forms with different properties

• The liquid becomes clearer