Unit 6

yikes!

breaking bonds

uses energy

forming bonds

gives off energy

system

changing bonds of molecules

endothermic

energy taken in for breaking > energy given off for forming (positive enthalpy)

exothermic

energy taken in for breaking < energy given off for forming (negative enthalpy)

phase changes

any change from less ordered to more ordered states is exothermic bc forming bonds releases energy

energetically favorable

going from higher to lower energy state

thermal equilibrium

average KE between two objects is the same (measure via temp)

to draw equilibrium line on graph

split the difference between high temp and low temp objects

heat capacity

amount of energy required to raise the temperature by 1 degree C or K (varies by substance, mass x c)

specific heat capacity

raising 1 g of substance by 1 degree (J/g degree C/K)

molar heat capacity

1 mol raised by 1 degree (J/mol degree C/K)

enthalpy of reaction

(sum of BE of bond broken) - (sum of BE of bonds formed)

has an enthalpy of formation of 0

pure elements in their standard states