Chemistry Test #5 Flashcards
Energy
Ability to do work
Kinetic Energy
Energy in motion
Potential Energy
Stored energy
Measuring heat energy
Joule/calorie
1 food calorie
1000 calories = 1 kilocalorie
calorie
amount of heat needed to raise 1 gram 1 degree celsius
Heat can be measured using a
calorimeter
temperaturer
average kinetic energy of particles
exothermic process
heat is released from the system into the surroundings
endothermic process
heat is absorbed from the surroundings into the system
more energy is released
exothermic
more energy is absorbed
endothermic
which way does heat flow
area of higher temperature to are of lower temperaturer
Absolute Zero (Kelvin):
-273K
Heating Curve
Solid, Melting, Liquid, Boiling, Gas
Flat Pat of Curve
Kinetic energy remains constant, potential energy increases as molecules spread apart
Rising Part of Curve
Kinetic Energy Remains contast, pE stays the same
Cooling Curve
Exothermic
Gas, Condensation, Liquid, Freezing, Solid
Condensation/Freezing
KE Constant, PE decreasing
Molecules move closer as intermolecular forces are formed
measures pressure that gases exert
barometer
standard pressure
1 ATM, or 101.3 kiloPascal
Kinetic Molecular Theory of Gases
indefinite volume & shape
spread far apart
move in straight line motion
net energy is conserved
volume of particles insignificant to amt of space occupied
no forces of attraction
temperature & pressure relationship
If pressure increases, volume decreases
If pressure decreases, volume increases
Real Gas Particles:
small volume
some attraction for each other
least ideal conditions
low temp, high pressure
turns gases into liquids; weak intermolecular forces will come into play
most ideal conditions
low pressure, high temperature
nonexistant attractive forces
far apart (like helium and hydrogen)
Avogadro’s Hypothesis
equal volumes of gases at the same temperature and pressure contain the same number of particles (molecules)
John Dalton: Partial Pressure of Gases
Total Pressure = sum of partial pressures
Sublimation
solid phase to a gas phase
Deposition
gas phase to solid phase
ice to water
heat of fusion
same temp and pressure
same density
as temperature increases,
vapor pressure increases
the weaker the force of attraction between the particles in a liquid,
the lower the energy level required to overcome it
absolute zero
-273C
0K
as molecules move apart
PE increases
when is the boiling point reached
when vapor pressure equals atm pressure
