Balancing Chemical Equations

What is the Law of Conservation of Mass?

• It states that no matter can be created or destroyed.
• It states that no energy can be created or destroyed.
• It states that matter can be created or destroyed.
• It states that no sound can be created or destroyed.

Tags

NGSS.HS-PS1-7

What is a coefficient?

• The small number on the right of the chemical symbol.
• The large number in front of a chemical formula.
• The number in between the chemical symbols.
• The number behind a chemical formula.

Tags

NGSS.MS-PS1-5

Is the equation balanced?: 2H₂O + O₂ --> 4MgO + 3Fe

• Yes
• No

Tags

NGSS.HS-PS1-7

What goes in the missing blanks?
SnO₂ + __ H₂ → Sn + __ H₂O

• 5
• 1
• 3
• 2

At the end of chemical reactions, what is the total mass of the reactants compared to the total mass of the products?

• the product is doubled
• the product is half the mass of the reactants
• the mass is the same
• the mass changes depending on the reaction

Tags

NGSS.HS-PS1-7

What is the little number after an element in a chemical equation called.
Example: H₂

• Coefficient 
• Subscript
• Atom
• Equation

When balancing equations a ____ can be placed to the left of a formula of a substance to make the equations balanced

• charge
• subscript
• random number
• coefficient

What coefficient should be used to make the following equation balanced?
N₂+O₂--> _NO 

• 1
• 2
• 3
• 4

Tags

NGSS.HS-PS1-7

Which of the following is an unbalanced equation?
(Check ALL answers)

• CaCO₃ --> CaO + CO₂
• PbO₂ + 2H₂-->2Pb + H₂O
• 2Na+ 2H₂O-->2NaOH + H₂
• CS₂ + 2O₂ --> CO₂ + 2SO₂

Tags

NGSS.HS-PS1-7

Which equation is balanced?

• PbO₂ + 2H₂

• SO₂ + H₂0 --> H₂SO₄

• 2Na + 2H₂O --> 2NaOH + H₂

Tags

NGSS.HS-PS1-7