Identifying Chemical Reactions

Which observation(s) might be used as evidence that a chemical reaction occurred?

• Color change
• Odor change
• Properties change
• All of the above

Tags

NGSS.MS-PS1-2

________ result(s) in no new substances.

• A physical change
• A chemical change
• Physical and chemical changes
• None of the above

If you start a chemical reaction with 5 atoms of helium, how many atoms will you have after?

• 4 atoms
• 10 atoms
• 1 atom
• 5 atoms

Tags

NGSS.HS-PS1-7

Which of the following help a chemical reaction to happen faster?

• Molecule
• Atom
• Catalyst
• Density

Tags

NGSS.HS-PS1-5

Is TNT exploding a physical or chemical change?

• Physical
• Chemical
• Both physical and chemical
• Neither physical nor chemical

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-4

NGSS.HS-PS1-7

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

Tags

NGSS.HS-PS1-7

Which type of chemical reaction has two or more reactants to make one product?

• combustion

• single displacement

• double displacement

• synthesis

• decomposition

Identify the following chemical reaction.

2 NaBr + 1 Ca(OH)₂ ----> 1 CaBr₂ + 2 NaOH

• Synthesis (or combination)

• Decomposition

• Single displacement

• Double displacement

Identify the following chemical reaction.

Pb + FeSO₄ ----> PbSO₄ + Fe

• Synthesis (or combination)

• Decomposition

• Single displacement

• Double displacement

What reaction has the following general formula:

AB --> A + B

• Combination

• Decomposition

• Single Replacement

• Double Replacement

• Combustion