Classifying and Balancing Chemical Reactions Review

In a chemical reaction what quantity is conserved?

• Mass
• Number of Atoms
• Number of Compounds
• Both Mass and Number of Atoms

In the equation, 2Mg + O₂ ---> 2MgO, which are the reactants?

• Mg and O
• MgO
• Mg and MgO
• O and MgO

In chemical reactions, the law of conservation of mass is......

• disobeyed
• does not apply
• obeyed
• used sometime

Balance this equation, Ca + H₂O --> CaO + H₂

• Ca + 2H₂O --> CaO + 2H₂
• 2Ca + H₂O --> CaO + H₂
• Ca + H₂O --> CaO + H₂
• Cannot be balanced

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

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

What type of reaction is this: CO₂ + H₂O --> H₂CO₃ 

• Decomposition
• Single Replacement
• Synthesis
• Combustion

What type of reaction is this, C₄H₁₂ + O₂ --> H₂O + CO₂

• Decomposition
• Single Replacement
• Double Replacement
• Combustion

What type of reaction is this: Cl₂ + 2KI _-->  I₂ + 2KCl

• Synthesis
• Single Replacement
• Double Replacement
• Decomposition

When a metal reacts with an acid what gas is formed? ex HCl + Zn --->

• H
• H₂
• Cl₂
• H₂O

Balance this equation:  H₂ + N₂ → NH₃

•  H₂ + 4N₂ → NH₃
•  H₂ + 3N₂ → 2NH₃
•  3H₂ + N₂ → 2NH₃
•  2H₂ + 2N₂ → 2NH₃