Mastery Checkpoint 5 Review

thermal energy

energy associated with motion of particles (unit is Joules)

Heat

transfer of thermal energy from one place to another (e.g. by collisions of molecules)

specific heat

energy required to raise 1g by 1 °C

molar heat capacity

energy required to raise 1 mol by 1°c

solid → liquid → gas

energy is absorbed

gas → liquid → solid

energy is released

what happens to temp during a phase change?

it stays the same

what is thermal energy doing during a phase change

overcoming IMF

what type of interactions are IMFs

Attractive interactions

heat

measure of transfer of thermal energy

entropy change (△H)

loss of gain of heat in a process

heat capacity

how much heat it takes to change substances temperature by the same amount

open system (biological systems)

can transfer energy and matter

closed systems (a closed system)

transfer energy but NOT matter

isolated system (insulated closed container)

no transfer of matter or energy

internal energy

sum of all the KE and PE of all particles in the system

state functions (denoted by upper case letters)

depend only on the initial and final states

path functions (denoted by lowercase letters)

depend on how change takes place

first law of thermodynamics

energy cannot be created or destroyed (but it can be transferred)

first law of thermodynamics formula

△E = q +w

△E = q +w

what type of functions are q & w

path functions

when is q (thermal energy change) a state function

when q is at a constant pressure

enthalpy

heat absorbed or emitted during a process under constant pressure

thermal energy formula

(mass x specific heat x temperature change)

q = m x c x △T

what does △H tell you about the system

whether heat is leaving the system (△H-) (heat is a product)

OR

entering the system (△H+) (heat is a reactant)

endothermic

absorbs heat/energy from surroundings to systems

exothermic

releases heat/energy from systems to surroundings

2nd law of thermodynmaics

for any change, the total entropy of the universe must increase

(heat always flows spontaneously from hotter to colder regions of matter)

3rd law of thermodynmaics

the entropy of a perfect crystal at absolute zero is zero

Change in T for S

↑ T = ↑KE =

↑S (S=entropy)

(higher temp means particles can distribute)

Phase Change for S

↑ disorder =

↑ S

dissolving gas in solution

↓ disorder =

↓ entropy

atomic size/complexity & S

↑ # of electrons/size of atom =

↑ S

atomic size/complexity & S

# of atoms in species =

↑ S

(as the # of atoms ↑, the # of bonds increase)