Transcript q_EQUATIONS.pptx

PHYSICAL PROCESS q EQUATIONS DECISION MAP
Q = mHf.
PHYSICAL PROCESS
HEAT EXCHANGE (q)
CALCULATION
1)
Hf = HEAT OF FUSION
TABLE B
1)
2)
3)
4)
5)
6)
7)
RECOGNIZE HINTS
NO ∆T.
FREEZING
MELTING
SOLID TO LIQUID,
LIQUID TO SOLID
AT 0.0 C (WATER)
CONSTANT TEMP
AT FREEZING
YES
IS THE SAMPLE AT THE
FREEZING POINT
NO
IS THERE A PHASE
CHANGE ?
NO
2)
3)
4)
5)
6)
RECOGNIZE HINTS
A ∆T.
1) 2 TEMPERATURES
GIVEN
2) ONE TEMP GIVEN
AND ONE ASKED
FOR.
HEATING
COOLING
HEAT EVOLVED
HEAT ABSORBED
HOW MANY J OR kJ need
to cause a certain ∆T.
Use
Q = mC∆T.
∆T = T2 – T1
1)
2)
3)
4)
5)
6)
7)
RECOGNIZE HINTS
NO ∆T.
CONDENSATION
EVAPORATION
LIQUID TO GAS, GAS TO
LIQUID
AT 100 C (WATER)
CONSTANT TEMP
AT BOILING POINT
Q = mHV
HV = HEAT OF VAPORIZATION TABLE B