Quiz: Balancing Equations

The (a)   explains why we must balance chemical equations.

• Law of Conservation of Mass
• Law of Gravity
• Law of Motion
• Law of Energy Transfer

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NGSS.MS-PS1-5

Which of the following equations is already balanced?

• 2H₂ + O₂ → 2H₂O

•  N₂ + H₂ → NH₃

• H₂ + O₂ → H₂O

• CH₄ + O₂ → CO₂ + H₂O

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NGSS.MS-PS1-5

What number is used to balance chemical equations by changing the quantity of molecules?

• Subscript

• Variable

• Exponent

• Coefficient

In the equation C + O₂ → CO₂, how many oxygen atoms are on each side?

• 2

• 3

• 4

• 1

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following equations is incorrectly balanced?

• 2H₂ + O₂ → H₂O

• 2Na + Cl₂ → 2NaCl

• Fe₂O₃ + 3CO → 2Fe + 3CO₂

• 4Al + 3O₂ → 2Al₂O₃

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Is this equation balanced?

• yes
• no
• Not enough information

Tags

NGSS.MS-PS1-5

In a balanced equation, the number of atoms of each element on the reactant side must be (a)   to the number of atoms on the product side.

• equal
• atoms
• reactants
• products

Tags

NGSS.MS-PS1-5

In the BALANCED equation 4Fe + ?O₂ → 2Fe₂O₃, what is the missing coefficient for O2?

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NGSS.HS-PS1-7

When balancing an equation, you cannot change the (a)   in a chemical formula because it would change the identity of the substance.

• subscript
• coefficient
• product
• reactant
• atoms

What is the missing coefficient for Na to balance this equation?

?Na + Cl₂ → 2NaCl

Tags

NGSS.MS-PS1-5