Chemistry Equations

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.MS-PS1-5

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

How many HCl molecules do you need to balance this equation? 
Mg +  __HCl --->  MgCl₂ + H₂

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-5

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

• 2,1,2,1

• 1,2,2,1

• 1,2,1,2

• 2,2,2,2

Tags

NGSS.MS-PS1-5

How many total atoms are in this formula?

• 1

• 2

• 6

• 7

Tags

NGSS.MS-PS1-1

This number is used to represent the number of each atom being represented.  What is the name of this number? 

• An Exponent

• The Coefficient

• A Molecule

• The Subscript

This appears on the left side of a chemical formula, and represents how many molecules there are. 

• An Atom

• The Subscript

• A Molecule

• The Coefficient

This appears on the left side of a chemical formula, and represents how many molecules there are. 

• A Molecule

• The Coefficient

You should do what with the coefficient and the subscript of an atom Ex: 2H2O (a)  

• Add

• Subtract

• Multiply

• Divide

Look at the image, and calculate which formula contains the most atoms of Oxygen

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-5