Endothermic/Exothermic Processes & Reactions

Exothermic EndothermicProcess • Heat exiting a substance

• Ex: water freezing• Physical change

• Heat entering a substance• Ex: water evaporating• Physical change

Reaction • Chemical reaction where energy is released in the form of light or heat

• Feels hot – chemical bonds forming

• Temp. change - warmer• Ex: Calcium & water

• Chemical reaction that absorbs energy from its surroundings

• Feels cold – chemical bonds breaking

• Temp. change - colder• Ex: Vinegar & baking soda

Reaction #1 - EndothermicBaking Soda & Citric Acid

Reaction #2 - ExothermicSteel Wool & Vinegar

Reaction #3 - ExothermicCalcium & Water

Reaction #4 - EndothermicBaking Soda & Vinegar

Time Temperature (⁰C)(sec.)

Time Temperature (⁰C)(min.)

Time Temperature (⁰C)(min.)

Time Temperature (⁰C)(sec.)

Graph Results• On one piece of graph paper.• Have a key to distinguish which line represents which

reaction.