Balancing Equations and Exothermic Reactions

What does the Law of Conservation of Mass state?

• Matter cannot be gained or lost in a chemical reaction.
• Matter can only be lost in a chemical reaction.
• Matter can only be gained in a chemical reaction.
• Matter can be gained and lost in a chemical reaction. 

Tags

NGSS.HS-PS1-7

What is the left part of a chemical equation called?
2H_{2 +} O₂ --> 2H₂O

• Reactants
• Products 
• Yields 
• Chemical Equation 

What is the right part of a chemical equation called...
2H_{2 +} O₂ --> 2H₂O

• Reactants
• Products 
• Yields 
• Chemical Equation 

Which of the following shows the correct way to balance the chemical equation?
Fe + O₂ -> Fe₂O₃

• 4Fe + 3O₂ -> 2Fe₂O₃
• 2 Fe + 3O₂ -> Fe₂O₆
• 4 Fe + O₆ -> 2Fe₂O₃
• None of the options are correctly balanced.

Tags

NGSS.HS-PS1-7

Which of the following reactions is balanced?

• 2CH₄ + O₂ -> CO₂ + H₂O
• CH₄ + 2O₂ -> CO₂ + H₂O
• CH₄ + 2O₂ -> CO₂ + 2H₂O
• None of the chemical equations are balanced.

Tags

NGSS.MS-PS1-5

Balance this equation...
HgO --> Hg + O₂

• It is balanced 
• 2HgO --> Hg + O₂
• 2HgO --> 2Hg + O₂
• I don't know...Oh well!

Tags

NGSS.HS-PS1-7

Balance this equation.
_CF₄ + _Br₂ -- _CBr₄ + _F₂

• 2,1,2,1
• 1,2,2,1
• 1,2,1,2
• 2,2,2,2

Balance this equation.
_CH₄ + _O₂ --> _CO₂ + _H₂O

• 1,2,1,1
• 2,1,2,1
• 1,2,1,2
• 0,2,0,2

Balance this equation
_Al +_HCl --> _H₂ +_AlCl₃

• 2, 6, 3, 2
• it is already balanced
• 4, 12, 3, 4
• 2, 1, 4, 5

Balance this equation.
_SnO₂ +_H₂-->_Sn +_H₂O

• 1,1,2,1
• 1,2,1,1
• 1,2,1,2
• 1,2,2,1