Review 4 Chemical Reactions

Marie had a beaker with a small amount of baking soda. She added a few drops of pickle juice to the baking soda and observed fizzing and bubbling. Based on her observation, which of these can Marie determine about the new substance formed by mixing the baking soda and pickle juice?

• A chemical reaction produced a solid.
• A chemical reaction produced a gas.
• No chemical reaction took place.
• Only a physical change happened.

Tags

NGSS.MS-PS1-2

Which of the following characteristics is shared by all chemical reactions?

• Produce a precipitate
• Show a color change
• Release heat energy
• Form new substances

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A student mixes two clear liquids together. After a few minutes, a white powdery solid can be seen settling on the bottom of the test tube. Which of the following is a conclusion that the student can draw based on these observations? The two clear liquids –

• were pure substances before they were mixed.
• are toxic and should be handled with extreme caution.
• have gone through a chemical change in which a new substance called a precipitate was produced.
• have been stored too long and are no longer good.

Tags

NGSS.MS-PS1-2

A student added white crystals to a clear liquid. The crystals dissolved in the liquid. After a few seconds, the liquid became quite warm and then turned bright red in color. Indications that a chemical change was taking place could be observed when –

• the white crystals were added to the clear liquid.
• the crystals dissolved in the liquid leaving only the liquid visible.
• There are no indications of chemical change
• the temperature of the liquid increased and an unexpected color change occurred.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS3-4

A student observes some sugar as it is heated and burns. The student concludes that a chemical reaction has occurred. Which of the following observations about the burning sugar provides evidence of a chemical reaction?

• Heat is added to the sugar crystals.
• The sugar melts and becomes a liquid.
• Gas is produced as the sugar turns black.
• No evidence of chemical reaction is present.

Tags

NGSS.MS-PS1-2

Which of the following observations is the best indicator that a new substance has been formed?

• A solid has become a liquid.
• A substance has changed color.
• A solid has dissolved in a liquid.
• The volume of a substance increased.

Tags

NGSS.MS-PS1-2

All of the following are evidence of a chemical change EXCEPT-

• change in state of matter
• formation of a gas
• color change
• precipitate forms

Tags

NGSS.MS-PS1-2

All of these are examples of physical changes except-

• dissolving sugar in tea
• boiling water
• corrosion
• melting ice cream

Tags

NGSS.MS-PS1-4

What is an example of a Chemical change?

• Ripped paper 
• boiled egg
• cracked egg
• sugar in water

• Physical Change
• Chemical Change

Tags

NGSS.MS-PS1-2

NGSS.MS-LS1-7