Chemistry Review Bell Ringers

Which problem is balanced?

• PbO₂ + 2H₂
• SO₂ + H₂0 --> H₂SO₄
• 2Na + 2H₂O --> 2NaOH + H₂

Tags

NGSS.HS-PS1-7

Balance this equation.
_SnO₂ +_H₂-->_Sn +_H₂O

• 1,1,2,1
• 1,2,1,1
• 1,2,1,2
• 1,2,2,1

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

• Coefficient 
• Subscript
• Atom
• Equation

What does the Law of Conservation of Mass state?

• Matter cannot be gained or lost in a chemical reaction.
• Matter can only be lost in a chemical reaction.
• Matter can only be gained in a chemical reaction.
• Matter can be gained and lost in a chemical reaction. 

Tags

NGSS.HS-PS1-7

Balance this equation
_Al +_HCl --> _H₂ +_AlCl₃

• 2, 6, 3, 2
• it is already balanced
• 4, 12, 3, 4
• 2, 1, 4, 5

Tags

NGSS.HS-PS1-7

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

The two sides of a chemical equation are called?

• Reactants (left) and Products (right)

• Ingredients (left) and Product (right)

• Cations and Anions

• Reactants (left) and Results (right)