Calorimetry and Phase Changes Flashcards
- the science of measuring changes in parameters of chemical reactions, physical changes, and ohase transitions
- “measuring heat”
Calorimetry
Qcan + Qwater + Qobj. = ______
0
if heat is gained, Q is _____
positive
if heat is lost, Q is _____
negative
” heat lost = heat gained “
Conservation of energy
any object/set of objects that we wish to consider
System
3 types of system
closed system
isolated
open system
in this system, no mass enters/leaves but energy can be exchanged w/ the environment
Closed system
in this system, no energy in any form passes across its boundaries
Isolated
- transition from one phase to another
- requires transfer of energy
Phase change
TRUE/FALSE.
During phase changes, the temperature of the mixture also changes.
FALSE. it does not change
solid to gas
sublimation
solid to liquid
melting
liquid to gas
eveaporation
liquid to solid
freezing
gas to liquid
condensation
gas to solid
deposition
the effect of adding heat to the system is ___________ but to ___________
not to increase the temperature
change its phase
- occurs at a definite phase transition temperature for a specific pressure
Phase Equilibrium Temperature
Phase equilibrium temperature is coexistence of 2 phases such that:
Freezing point = _______
Boiling point = _______
melting point
condesation point
measure of the energy needed to melt a solid substance
Latent heat of Fusion
Latent heat of fusion.
Lf of ice = _____
334 x 10³ J/kg
Latent heat of fusion, Lf.
if solid to liquid:
Q is (+ or - )
the object (gained/lost) energy
+
gained
Latent heat of fusion, Lf.
if liquid to solid:
Q is (+ or - )
the object (gained/lost) energy
- lost
