Balancing Reactions

The number of atoms you begin with in a chemical reaction ...

• must be the same as the number of  atoms you end with

• must be an even number

• can be different to the number you finish with

• changes depending on how much energy is formed

Tags

NGSS.MS-PS1-5

Fill in the blanks with coefficient:
PCl₅+_ H₂O→_ HCl+H₃PO₄

• 4, 5

• 1, 6

• 3, 8

• 2,2

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

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

(We know we usually don't write 1 when balancing and equation)

• 1,2,1,1

• 2,1,2,1

• 1,2,1,2

• 0,2,0,2

Tags

NGSS.MS-PS1-5

In balancing chemical equations, we change

• Coefficients

• Subscripts

• Both can be changed

• None can be changed

What coefficient will go in front of the Na to balance this equation?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-5

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-5

What are the smaller numbers that you CANNOT change in a chemical equation? 

• Coefficient

• Products

• Reactants

• Subscript

Tags

NGSS.MS-PS1-1

What are the larger numbers that you CAN CHANGE in a chemical equation? 

• Coefficient 

• Products

• Reactants

• Subscripts

How many atoms of aluminum are on each side of the following equation: 4Al + 3O₂ --> 2Al₂ O₃

• 2

• 6

• 1

• 4

Tags

NGSS.MS-PS1-1

At the end of chemical reactions, what is the total mass of the reactants compared to the total mass of the products?

• the product is doubled

• the product is half the mass of the reactants

• the mass is the same

• the mass changes depending on the reaction

Tags

NGSS.MS-PS1-5