HW - HEAT CURVE
NAME_______________________
The graph shown below represents a sample heating curve for a substance. Use it to answer the questions below:
90
E
80
T
E
M
P
(oC)
70
D
60
50
40
C
30
20
10
B
0
-10
A
10
20 30 40 50 60 70 80 90 100 110 120
TIME (min)
________________________ 1) What phase (or phases) are present during segment A?
________________________ 2) segment B?
________________________ 3) segment C?
________________________ 4) segment D?
________________________ 5) segment E?
________________________ 6) What phase change, if any is occuring during segment A?
________________________ 7) segment B?
________________________ 8) segment C?
________________________ 9) segment D?
________________________ 10) segement E?
________________________ 11) Which H equation would you use to calculate the heat absorbed by the
substance during segment A?
________________________ 12) segment B?
________________________ 13) segment C?
________________________ 14) segment D?
_______________________ 15) segment E?
_______________________ 16) What is the melting point for this substance?
_______________________ 17) What is the boiling point for this substance?
_______________________ 18) How long did it take for the substance to heat up to the melting point?
_______________________ 19) How long did it take for the substance to melt?
_______________________ 20) How long did it take for the substance to heat up to the boiling point?
_______________________ 21) How long did it take for the substance to boil?
HW - HEAT CURVE
NAME_______________________
22) Vapor Pressure and Boiling. The following graph shows vapor pressure curves for two substances, A and B:
Vapor Pressure Curve for Two Substances
160
150
140
130
120
110
Vapor pressure (kPa)
100
A
90
80
70
B
60
50
40
30
20
10
10
50
100
Temperature (oC)
___________ a) What is the vapor pressure (in kPa) of A at 30 oC?
_____________ b) What is the vapor pressure of B at 30oC?
_____________ c) At what temperature is the vapor pressure of A 80 kPa?
_____________ d) What is the vapor pressure of B at the temperature from (c)?
_____________ e) At what temperature is the vapor pressure of B equal to 80 kPa?
_____________ f) Boiling of a liquid occurs when the vapor pressure equals what quantity?
_____________ g) The “normal boiling point” is the boiling temperature at standard pressure. What is
standard pressure in kPa?
_____________ h) What is the normal boiling point of A?
_____________ i) What is the normal boiling point of B?
_____________ j) At what temperature would A boil in Denver, CO if the atmospheric pressure there were
90 kPa?
_____________ k) What would the atmospheric pressure have to be for B to boil at the temperature in (j)?