thermo chemistry Flashcards
Law of conservation of energy
energy cannot be created or destroyed (can change forms)
photosynthesis
6 CO2 (g) + 6 H2O (l) + energy —-> C6H12O6 (s) + 6 O2 (g)
cellular respiration is
the opposite reaction of photosynthesis
Kinetic energy / EK is
the motion of molecules ( average temperature)
Energy is mesured in?
joules
Potential energy / EP is
The energy stored in the bonds
enthalpy
EK + EP
Physical change is a
state or phase change. Nothing new. (liquid to gas is endothermic) (gas to liquid is exothermic)
Chemical change
chemical reactions. (broken and made bonds)
Thermochemistry is
the study of energy changes by a system during a chemical reaction
heat flows from hot to cold until
equilibrium
heat capacity is
j/ g times degrees
for water one mL is equivalent to
1 gram
the formula for kinetic energy (the surroundings) is
Q= mc delta t
mass, heat capacity and chage in temperature
Positive enthalpy is
the system gaining energy (endothermic)
Calorimetry
quantifying energy change
caloremeter
isolated system for tracking energy change
Q
heat gained or loss in reaction is
- -Q=+Q
Bomb calorimeter
combustiom reaction
Q= C delta T
no mass will be given or asked for
Endo thermic qualities
reactants are more stable than products
energy on reactent side
energy needed
T down, EK down, EP up
exo thermic qualities
reactants are less stable than products
energy is released
energy is a product
T up, EK up, EP down
delta rH means what
change in enthalpy
Molar enthalpy is
n x rHm
m means moles KJ/mol
Aqueous molecules have the same conversion as
water
