Unit 6 Test Flashcards
Endothermic equation
🔺h on the left (reactants)
Heat goes into the equation
Positive
Exothermic reaction
🔺h on the right side (products)
Heat exits the reaction
Negative
Calorimeter
Device that measures the release of heat
Enthalpy of Reaction
Net Energy change during a chemical reaction
Enthalpy of formation
Energy change when a mole of a compound is formed from elemental states
Heat of reaction equation
🔺H rxn= E hf product- E hf reactants
Molar heat of fusion-
Energy required to melt Solid to liquid of a substance
Breaks bonds
Molar heat of vaporization
Energy required to go liquid to gas
Endothermic
Molar heat of condensation
Energy to go gas to liquid
Exothermic
Freezing phase change
Exothermic
Liq to solid
Melting
Endothermic
Sublimation
Solid to gas
Endothermic
Deposition
Gas to solid
Exothermic
Phase change opposites
Melting & freezing
Vaporization & condensation
Sublimation& deposition
Heating curve graph
Doesn’t change temp in a phase change
Only in same phase
System
The 1 thing that changes when heated up - breaking of the bonds
Surrounding
Things around the system that are affected
Calories
Energy required to raise one gram of H20
Food calorie
= to 1000 calories
Hest capacity
Heat required to raise the temperature of an object 1 degree
Things with a high heat capacity
Heats up slowly
Cools down slowly
Large amount of energy to change temperature
Things with a low heat capacity
Small amount to change temp
Heats up quickly
Cools down quickly
Readjusts to new conditions
Q= mcp🔺t
Energy = mass heat capacity t final - t initial
Heat / Enthalpy
Flow of energy from hot to cold
Why does the temperature not increase during a phase change
The intermolecular bonds are breaking and spreading fathr apart
Calorimetry
Heat of system = - heat of surrounding
