Calorimetry

Unit 1: Lesson 2

Heat capacity is measured in J/g Celcius

Calorimetry: when we measure the changes of energy during a chemical or physical change

Calorimeter: is a device used to measure the energy changes

Additional comments: If we put zinc in HCL as the zinc dissolves and replaces the HCL and we keep it in that system the temperature will change. -We ignore the stuff that goes outside the environment. - any aqueous solution will have the same density or heat capacity as water. Everything that’s a solution is the same as water

• The system is the reaction while the surrounding is everything that is directly involved in the reaction for example water molecules surrounding an acid is considered to be the surrounding.

Calorimetry Calculations:

q= mc△T and q_system+q_surroundings =0 or q_system= -q_surroundings

q=the total amt of thermal energy absorbed

m= mass of sample

c= specific heat capacity J/g Celcius J/g K

T= temperature change measured in Celsius or K

Questions/Concerns: How do you know which formula to use for a problem? How do you tell which formula is the right one to use? What is each formulas purpose?