Unit 21-24 Assessment

In this image, the information in red is called the_______.

• Products
• Reactants
• Chemical Subscript
• Ingredients

In this image, the information to the right of the arrow (in black) is called the_______.

• Product
• Reactant
• Chemical Subscript
• Final chemical

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. 

How many ELEMENTS are in the compound H₂O

• 1
• 2
• 3
• 4

How many ELEMENTS are in the compound O₂

• 1
• 2
• 3
• 4

How many ATOMS of Carbon are in 3C₂H₄O

• 2
• 3
• 4
• 6

Balance this equation,            Al₂O₃ ---> Al + O₂ 

• Cannot be balanced
• 2Al₂O₃ ---> 2Al + 3O₂ 
• 2Al₂O₃ ---> 4Al + 3O₂ 
• 3Al₂O₃ ---> 2Al + O₂ 

How many atoms of lead (Pb) are in Pb(NO₃)₂?

• 1
• 2
• 3
• 6

__ Al + __ FeO → Al₂O₂ + __ Fe

• 1, 1, 2

• 2,1,2

• 2, 2, 2

• 2,4,2

 Mg  +  ___ HCl  →   MgCl₂  +   H₂

• 1
• 2
• 3
• 4