Unit 4-balancing chemical equations

The Law of Conservation of Matter

• tells how many atoms of an element are contained in one molecule or formula unit.

• the starting materials in a chemical reaction

• the new substances that are formed in a chemical reaction

• A law stating that atoms are not created or destroyed during a chemical reaction.

Tags

NGSS.MS-PS1-5

Is the equation balanced?: 2H₂O + O₂ --> 4MgO + 3Fe

• yes

• no

Tags

NGSS.MS-PS1-5

Balance this equation

_Al +_HCl --> _H₂ +_AlCl₃

• 2,6,3,2

• it's already balanced

• 4,12,3,4

• 2,1,4,5

Tags

NGSS.MS-PS1-5

The coefficient in 3H₂O is

• 6

• 5

• 2

• 3

Tags

NGSS.MS-PS1-1

How many atoms of carbon (C) are in C₆H₁₂O₆?

• 3
• 6
• 12
• 24

Tags

NGSS.MS-PS1-1

How many Sodium (Na) are in 6NaCl?

• 1
• 12
• 6

Tags

NGSS.MS-PS1-1

How many Hydrogen are in 4H₂O?

• 6
• 8
• 2
• 4

Tags

NGSS.MS-PS1-1

Is this equation balanced?

• yes
• no
• Not enough information

Tags

NGSS.MS-PS1-5

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

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

• 1
• 2
• 3
• 4

Tags

NGSS.MS-PS1-5