Phases Flashcards
which bonds are broken in a physical (ex. phase) change?
intermolecular forces between molecules or atoms, no intramolecular bonds are made or broken
the higher the average kinetic energy of the molecule of a substance…
the greater its entropy
phase changes are the result of:
breaking (or forming) intermolecular interactions
which phase is the most ordered and least energetic of the phases?
solid
heat of transition
the energy required to complete a transition
heat of fusion
the amount of heat that must be absorbed to change a solid into a liquid
heat of vaporization
the energy absorbed when a liquid changes to a gas
deposition
gas to solid
sublimation
solid to gas
crystallization
liquid to solid
condensation
gas to liquid
fusion
solid to liquid
vaporization
liquid to gas
what is the magnitude of the heat of transition for each phase change directly related to?
the strength and number of the intermolecular forces that substances experiences
what does the amount of heat required to cause a change of phase depend on?
the type of substance and the amount of substance
what is the result of matter absorbing or releasing energy in between phase changes?
increase or decrease in the temperature of the substance, NO PHASE CHANGE
what is the result of matter absorbing or releasing energy while undergoing a phase change?
phase change but no change in temperature
heat capacity C
the constant of proportionality that describes the amount of heat absorbed or released by a sample in relation to its change in temperature
specific heat, c
C=mc, an intrinsic property of the substance that tells us how resistant the substance is to changing temperature
calorie
the amount of heat required to raise the temperature of 1 gram of water by 1 degrees Celsius
temperature change is proportional to ______ and inversely proportional to _______
proportional to the heat absorbed, inversely proportional to the substance’s heat capacity
what does the specific heat of a substance also depend on?
the phase of the substance
what is the SI unit for energy?
joule
phase transition diagram/heating curve
plots the temperature of the sample vs. the amount of heat absorbed
aside from temperature, what else does the phase of the substance depend on?
pressure
phase diagram
figure that shows how phases are determined by temperature and pressure
what do the boundary lines between phases in a phase diagram represent?
the points at which the two phases are in equilibrium (i.e. phase change)
when are solid phases favoured?
low temperatures and high pressure
when are gas phases favoured?
high temperatures and low pressure
normal melting point
the temperature at the point where the 1atm pressure line in a phase diagram crosses the solid-liquid boundary
normal boiling point
the temperature at the point where the 1atm pressure line in a phase diagram crosses the liquid-gas boundary
triple point
the temperature and pressure at which all three phases exist simultaneously in equilibrium, and therefore all phase changes are happening simultaneously
critical point
marks the end of the liquid-gas boundary. beyond this point, substance displays properties of both liquid (high density) and gas (low viscosity), it thus becomes a supercritical fluid
supercritical fluid
where the liquid and gas phases are no longer distinct
what is exceptional about water and it’s phase diagram?
water is denser in the liquid phase than in the solid phase, the solid-liquid boundary line has a slightly negative slope compared to most other substances
