Evidences 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.

• Water is produced. 

Tags

NGSS.MS-PS1-2

The following are the evidences that chemical reaction took place, EXCEPT:

• evolution of gas

• formation of precipitate

• formation of new element

• change in the intrinsic properties

Tags

NGSS.MS-PS1-2

What are the products in the equation?

• Zn and CuSO₄

• Zn and Cu

• ZnSO₄ and Cu

• Zn only

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following chemical reaction shows the production of water from hydrogen gas and oxygen gas?

• 2 H₂O → 2 H₂ + O₂

• 2 H₂ + O₂ → 2 H₂O

• 3 H₂ + O₂ → 3 H₂O

• 3 H₂O → H₂ + 3 O₂

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following best describes the combustion reaction?

• hydrocarbon combines with oxygen to produce CO₂ and H₂O

• hydrogen combines with CO₂ to produce O₂ and H₂O

• hydrocarbon combines with H₂O to produce CO₂ and O₂

• CO₂ combines with oxygen to produce hydroxide and H₂O

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

NGSS.MS-PS1-5

Quicklime ( CaO ) is used as a drying agent. When water is added to this, slaked lime Ca(OH)2 is formed. What type of reaction is this?

• combination

• single displacement

• decomposition

• double displacement

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What are the evidences of a chemical reaction?

• Color , temperature

• Gas, precipitate

• Light

• All above

Tags

NGSS.MS-PS1-2

Select the 1 evidence that support this chemical reaction.

• Odor

• Color change

• Gas production

• Light production

Tags

NGSS.MS-PS1-2

Select the 1 evidence that supports this chemical reaction.

• Odor

• Temperature change

• Gas production

• Color Change

• Light production

Tags

NGSS.MS-PS1-2

Select the 1 evidence that supports this chemical reaction.

• Precipitate

• Odor

• Light production

• Color change

• Gas production

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5