Balancing Chemical Equations and Types of Reactions Practice

• 3
• 2
• 1
• 4
• 5

How many HCl molecules do you need to balance this equation?

2Mg + ​ (a)   HCl ---> 2MgCl₂ + 2H₂

• 4
• 1
• 2
• 3

Balance this equation:

​ (a)   N₂ + ​ ​ (b)   H₂ --> ​ (c)   NH₃

• 1
• 3
• 2
• 4
• 5

According to the Law of Conservation of Mass (Matter), Matter cannot be ​ (a)   or ​ (b)   , it can only be ​ (c)   . This means however many atoms of an element we have before a reaction must be ​ (d)   to the number after a reaction.

• created
• destroyed
• changed
• equal
• unequal

In 3P₂O₅,

there are ​ (a)   phosphorus (P) atoms

and ​ (b)   oxygen (O) atoms.

• 6
• 15
• 8
• 3
• 12
• 21

Balance the following chemical equation.

​ (a)   C₂H₄ + ​ ​ (b)   O₂ --> ​ (c)   CO₂ + ​ (d)   H₂O

• 1
• 3
• 2
• 4
• 5

How many Hydrogen atoms are in 4 H₂O? ​ (a)   How many oxygen atoms? ​ (b)  

• 8
• 4
• 1
• 2
• 3
• 5
• 6
• 7
• 9

How many elements are in 2 C₆H₁₂O₇? (a)  

How many C: ​ (b)  

How many H: ​ (c)  

How many O: ​ (d)  

How many TOTAL atoms: ​ (e)  

• 3
• 12
• 24
• 14
• 50
• 7
• 6
• 25
• 52
• 60

Match the formula to the description:

• 3 sulfur's, 12 oxygen's

• SO₄

• 1 sulfur, 4 oxygen's

• SO₃

• 1 sulfur, 3 oxygen's

• 2 SO₃

• 2 sulfur's, 6 oxygen's

• 3 SO₄

• 4 sulfur's, 6 oxygen's

• 2 S₂O₃

Put the elements in order from smallest to largest number of atoms:

2 C₃H₅(NO₃)₄

• carbon

• nitrogen

• hydrogen

• oxygen