8.5E Evidence of a chemical reaction and law of conservation of mass

• The student can use the different colored dots to show no new substance was created from the original molecules

• The student can use the different colored dots to show a new substance was created from the original molecules

• This model does not show that a chemical reaction occurred

• The student can use the different colored dots to show a new element was formed from the original elements

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A student mixes two liquids together and notices that a white solid has formed at the bottom of the container. What can the student conclude?

• 1 and 2 only

• 1, 3, and 4 only

• 1, 2, and 4 only

• 3 only

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Two chemicals are mixed and sealed in a plastic bag. The bag begins to inflate and becomes hot to the touch. What evidence can the student cite to show a chemical reaction occurred?

• Formation of a gas

• Increase in temperature

• Formation of a gas and increase in temperature

• No chemical reaction

Tags

NGSS.MS-PS1-2

Which of the following could be the hypothesis supported by an investigation that demonstrates the law of conservation of mass in relation to chemical reactions?

• If the reaction obeys the law of conservation of mass, then mass will be the same before and after the reaction

• If the reaction obeys the law of conservation of mass, then the mass will increase after the reaction

• If the reaction obeys the law of conservation of mass, then the mass will be different before and after the reaction

• If the reaction obeys the law of conservation of mass, then the mass will decrease after the reaction

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Students X and Y mix two clear liquids together during a laboratory investigation. They notice the color of the new solution is red. Student X concludes there has been a chemical reaction. Student Y concludes there has not been a chemical reaction. Which student drew a valid conclusion based on the information provided?

• Student X is correct because When two liquids are poured together there is a chemical reaction

• Student Y is correct because color is a physical property, not a chemical property

• Student X is correct because a change in color is evidence of a chemical reaction

• Student Y is correct because there must be bubbling if there is a chemical reaction

Tags

NGSS.MS-PS1-2

Which statement is NOT evidence that a new substance has formed during a chemical reaction?

• Gas is produced

• Temperature changes

• Precipitate forms

• Substance melts

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

During an investigation, students mix an unknown powder and unknown liquid. When the students pour the liquid into the powder, bubbles are produced. Which statement correctly identifies the type of investigation?

• The powder and liquid repel one another and produces bubbles

• The powder and liquid produce bubbles because the law of conservation of mass is violated

• The powder and liquid produce bubbles because a chemical reaction occurs

• The powder and liquid produce bubbles because a physical change occurs.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What evidence of chemical reaction will be observed based on this chemical reaction?

• Gas formation

• Flash of light

• Decrease in mass

• Formation of precipitate

Tags

NGSS.MS-PS1-2

Which description provides evidence that chemical reactions form new substances with different chemical properties?

• Bubbles formed in a bathtub

• Food coloring added to water

• Butter melted in a pan

• Eggs fried in a skillet

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which investigation results do NOT represent evidence of a chemical reaction?

• 
• 
• 
• 

Tags

NGSS.MS-PS1-2