Calorimetry PPT

Calorimetry Unit 2

1. Definitions

• Universe: Everything in existence.

  • Included everything that is observed.

• System: A subset of the universe that is being studied/measured.

• Surroundings: All parts of the universe that are not considered in the system.

  • Example in Cheeto Lab:

    • System: Cheeto being burned.

    • Surroundings: Soda can, water, thermometer, etc.

2. Law of Conservation of Mass

• States that matter cannot be created or destroyed in chemical reactions.

  • Mass before reaction = Mass after reaction.

3. Calorimetry

• Calorimetry: Accurate and precise measurement of heat flow during chemical and physical processes.

• Calorimeter: Equipment designed to measure energy changes during chemical reactions or phase changes.

4. Signs of a Chemical Reaction

• Five main indicators:

  • Light production

  • Temperature change

  • Gas released

  • Color formation

  • Formation of a precipitate

5. Temperature Changes in Reactions

• Exothermic Reactions:

  • Release energy, feel hot to the touch.

• Endothermic Reactions:

  • Absorb energy, feel cold to the touch.

6. Exothermic Reaction Example 2

• Reaction: Magnesium (Mg) + Hydrochloric Acid (HCl) → Hydrogen gas (H2) + Magnesium Chloride (MgCl2).

  • This is an exothermic reaction.

  • Questions:

    1. Is energy released or absorbed? (Released)

    2. Is energy a reactant or a product? (Product)