Evidence of Chemical Reaction

Hydrogen peroxide breaks down to form water and oxygen gas. Which observation is evidence that a chemical reaction has occurred?

• The mass of the solution remains the same.

•  Phase changes are observed.

•  The color of the solution remains clear.

• The temperature of the solution increases. 

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A clear liquid from a flask is poured into another clear liquid in a beaker. Which of the following results of this procedure would indicate a new substance was formed?

• The level of the substance in the beaker is higher after the other liquid is added.

• A yellow solid forms and then settles to the bottom of the beaker.

• Small white crystals are left behind in the flask that held the first liquid.

Tags

NGSS.MS-PS1-2

Evidence of a chemical reactions is anything that shows - 

• a new substance has formed

• a solid dissolved in a liquid

• interaction between 2 gases

• a change in the state of matter

Tags

NGSS.MS-PS1-2

_______________ is an example of both a color change and new substance produced from a chemical change with oxygen and metal.

• shredded paper

• rust (iron oxide)

• wood chips

• melted wax

Tags

NGSS.MS-PS1-2

Which is an example of a chemical change?

• Burning wood

• Rust on a car

• Cooking food

• All of the above

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following help a chemical reaction to happen faster?

• Molecule

• Atom

• Catalyst

• Density

Which of these is NOT a sign that a chemical change has occurred?

• A loss of transparency

• An unexpected color change

• A temperature change

• The formation of a precipitate

Tags

NGSS.MS-PS1-2

Rotting Fruit (Like a brown banana)

• Physical Change

• Chemical Change

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which is not a sign that a chemical reaction has occurred.

• A change in mass

• bubbling

• production of an odor or smell

• change in color

Tags

NGSS.MS-PS1-2

Which is not evidence that a chemical reaction has occured

• Production of flames

• Change in temperature or heat

• freezing

• Production of light

Tags

NGSS.MS-PS1-2