Balancing Chemical Equations 2

In every balanced chemical equation, each side of the equation has the same number of ____.

• atoms of each element
• moles
• molecules
• coefficients

Which of the following is the correct skeleton equation for the reaction that takes place when solid phosphorus combines with oxygen gas to form diphosphorus pentoxide?

• P + O₂ --> PO_2
  
• P + O --> P_5O_2
  
• P + O_2 --> P_2O_5
•  P_2O_5 --> P + O_2
  

Chemical equations ____.

• describe chemical reactions
• show how to write chemical formulas
• give directions for naming chemical compounds
• describe only biological changes

Chemical reactions ____.

• occur only in living organisms
• create and destroy atoms
• only occur outside living organisms
• make new products

What are the coefficients that will balance the skeleton equation below?  
N _2+ H_2 -->  NH_3 

• 1,1,2
• 1,3,3
• 3,1,2
• 1,3,2

A catalyst is ____.

• the product of a combustion reaction
• not used up in a reaction
• a reactant
• a solid product of a reaction

In the chemical equation H_2O_2 --> H_2O + O_2 the O_2  is a ____.

• catalyst
• solid
• product
• reactant

Which of the following reactions is balanced?

• 2CH_4 + O_2 -> CO_2 + H_2O
• CH_4 + 2O_2 -> CO_2 + H_2O
• CH_4 + 2_O_2 -> CO_2 + 2H_2O
• None of the chemical equations are balanced.

Which scientific law is the reason equations must be balanced? 

• Lay of Conservation of Energy
• Law of Conservation of Mass
• Newton's Laws of Motion
• Law of Definite Proportions

Which of the following shows the correct way to balance the chemical equation?
Fe + O_2 -> Fe_2O_3

• 4Fe + 3O_2 -> 2Fe_2O_3
• 2 Fe + 3O_2 -> Fe_2O_6
• 4 Fe + O_6 -> 2Fe_2O_3
• None of the options are correctly balanced.