Chemical Reactions

In a chemical equation, is it true that -

• the reactant side and product side can have different numbers of atoms for each element
• there can be different elements on the reactant side and the product side
• an element or compound must be accompanied by a phase change
• the coefficients indicate the number of molecules of each reactant used and the number of molecules of each product made

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The formula below represents the most common carbohydrate known as glucose. Which information can be determined from the chemical formula?
C₆H₁₂O₆

• The structural arrangement of the atoms in a glucose molecule
• The color of a glucose molecule
• The size of a glucose molecule
• The number of atoms of each element in a glucose molecule

Tags

NGSS.MS-PS1-1

For an investigation a student poured a blue solution of CuSO₄ into a beaker. The student placed a shiny, silver-colored strip of zinc metal in the solution and observed the changes.
The student inferred that a chemical reaction occurred. What evidence supports this inference?

• A dark solid formed on the zinc metal.
• 
  The zinc metal remained silver-colored and shiny
• The CuSO₄ solution turned blue when the zinc metal was added.
• None of these

Tags

NGSS.MS-PS1-2

The reactants are on the left side of the chemical equation.

• True
• False

Tags

NGSS.MS-PS1-5

Two clear colorless solutions were combined.
The student observed that the temperature changed from 25 •C to 23 •C when the solutions were combined and that a white substance rapidly formed and settled to the bottom of the container. What most likely happened to produce these results?

• One of the original compounds came out of solution
• The solutions reacted chemically
• Some of the water froze into ice crystals
• Rapid evaporation of water occurred, leaving a solid

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

In which of these compounds are there twice as many oxygen atoms as hydrogen atoms?

• H₃PO₄
• H₂SO₄
• HCIO₃
• H₂0

Tags

NGSS.MS-PS1-1

How many atoms in all are in a molecule of serotonin?

C₁₀H₁₂N₂O

• 22
• 24
• 25
• 4

Tags

NGSS.MS-PS1-1

In a ___________change, a substance changes into a different substance.

• Physical

• Chemical

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

4Si + S₈ --> 2Si₂S₄

• Synthesis
• Decomposition
• Single displacement
• Double displacement

Tags

NGSS.MS-PS1-2

3Ca + 2AlCl₃ --> 3CaCl₂ + 2Al

• Synthesis
• Decomposition
• Single diplacement
• Double displacement

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5