1 Chemical Equation Review

The law of conservation of mass states that matter ___________________.

• cannot enter into chemical reactions

• cannot be created or destroyed

• cannot form different substances

• cannot be modeled

Which of the following represent chemical equations? Check all that apply.

• $2Na\ +\ H_2O\ \rightarrow\ 2NaOH\ +\ H_2$

• $2KClO_3\ \ \rightarrow\ 2KCl\ +\ 3O_2$

• $2Fe\ +\ 3O_{2\ }\rightarrow\ 2Fe_2O_3$

• $2H_2O$

• $3O_3\ ,\ H_2O$

 $C_2H_6\ +\ 5O_2\ \rightarrow\ 2CO_2\ +\ 3H_2O_2$  
Given this chemical equation, what are the REACTANTS?

•  $C_2H_{6\ }and\ 5O_2$  

•  $2CO_2\ and\ 3H_2O_2$  

The formula shown here represents the breakdown of a metal into rust. What elements are involved in this reaction? Check all that apply. $4Fe\ +\ 3O_2\ \rightarrow\ 2Fe_2O_3$  

• Iron

• Oxygen

• Carbon

• Nitrogen

Is this balanced?...
Al + O₂ --> 2Al₂O₃

• Yes!
• NO!

4Si + S₈ --> 2Si₂S₄

• Synthesis
• Decomposition
• Single displacement
• Double displacement

3Ca + 2AlCl₃ --> 3CaCl₂ + 2Al

• Synthesis
• Decomposition
• Single diplacement
• Double displacement

3KOH + H₃PO₄ --> K₃PO₄ + 3H₂O

• Synthesis 
• Decomposition
• Single displacement
• Double displacement

2Pb(NO₃)₂ --> 2PbO + 4NO₂ + O₂

• Synthesis 
• Decomposition
• Single displacement
• Combustion

C₄H₁₂ + O₂ --> CO₂ + H₂O

• Synthesis
• Combustion
• Single Replacement
• Double Replacement