Chemical reactions

Is this chemical equation balanced?

• yes

• no

In this chemical reaction, what is the coefficient on H₂?

• 1

• 2

• 3

• 4

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

• Physical
• Chemical

Which of these is NOT a sign that a chemical change has occurred? 

• A loss of transparency 
• An unexpected color change
• A temperature change
• The formation of a precipitate

The Law of Conservation of Mass states

• that matter exists in all states and reacts the same
• that matter can only be changed into new substances by introducing a catalyst
• that matter exists in the same state throughout any chemical change
• that matter cannot be created or destroyed and that the mass of the products must equal the mass of the reactants

How many Al atoms are in this compound?         4Al₂O₃

• 2
• 8
• 6
• 4

How many F atoms are in this compound?
6MgF₂ 

• 2
• 6
• 8
• 12

a copper penny turning greenish after a few years.

• Chemical Change
• Physical Change

An gel ice pack getting cold after you put it in the freezer for an hour.

• Chemical Change
• Physical Change

In a chemical reaction, the mass of the reactants is 200 grams. Which of the following could represent the mass of the products?

• 2000 g

• 20 g

• 200 g

• 2g