Balancing Chemical Reactions

Solve the problem: Al + O2 --> Al2O3

• 4Al + 3O2 --> 2Al2O3
• 2Al + 4O2 --> Al2O3

Solve the problem: Al + S --> Al2S3

• Al + 2S --> 2Al2S3
• 2Al + 3S --> Al2S3

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

• Yes
• No

What is a closed system?

• A system in which energy does not travel freely.
• A system in which energy travels freely.

What is a reactant?

• The chemical substances that begin the reaction.
• What comes from the reaction.

Tags

NGSS.MS-PS1-2

Is this equation balanced?:                                                     CS2 + 202 --> CO2 +2SO2

• Yes
• No

What is a yield?

• The arrow in an equation that represents the chemical reaction.
• The beginning substances.

Solve the problem: N2 + O2 --> 2NO

• N2 + O2 --> 2NO
• 2N2 + O2 --> 2NO

A synthesis occurs when...

• Two formulas combine.
• A formula breaks apart.
• An atom is replaced during a reaction.

Which problem is balanced?

• PbO2 + 2H2
• So2 + H20 --> H2SO4
• 2Na + 2H2O --> 2NaOH + H2