1. Chapter 2 Energy and Matter
2.3
Temperature Conversions
Copyright © by Pearson Education, Inc.
Publishing as Benjamin Cummings

2. Temperature Temperature
is a measure of how hot or cold an object is compared to another object.
indicates that heat flows from the object with a higher temperature to the object with a lower temperature.
is measured using a thermometer.
Copyright © by Pearson Education, Inc.
Publishing as Benjamin Cummings

3. Temperature Scales Temperature Scales
are Fahrenheit, Celsius, and Kelvin.
have reference points for the boiling and freezing points of water.
Copyright © by Pearson Education, Inc.
Publishing as Benjamin Cummings

4. Learning Check A. What is the temperature of freezing water?
1) 0°F ) 0°C ) 0 K
B. What is the temperature of boiling water?
1) 100°F ) 32°F ) 373 K
C. How many Celsius units are between the boiling and freezing points of water?
1) ) ) 273

5. Solution A. What is the temperature of freezing water? 2) 0°C
B. What is the temperature of boiling water?
3) 373 K
C. How many Celsius units are between the boiling and freezing points of water?
1) 100

6. Fahrenheit Formula
On the Fahrenheit scale, there are 180°F between the freezing and boiling points and on the Celsius scale, there are 100°C.
180°F = 9°F = 1.8°F
100°C 5°C 1°C
In the formula for the Fahrenheit temperature, adding 32 adjusts the zero point of water from 0°C to 32°F.
TF = 9/5 TC  or
TF = 1.8 TC 

7. Celsius Formula TC is obtained by rearranging the equation for TF.
TF = TC
Subtract 32 from both sides.
TF = 1.8TC ( )
TF = 1.8TC
Divide by 1.8 = °F = TC
TF = TC
1.8

8. Solving A Temperature Problem
A person with hypothermia has a
body temperature of 34.8°C. What is that temperature in °F?
TF = 1.8 TC 
TF = 1.8 (34.8°C) °
exact tenth's exact
= °
= 94.6°F
tenth’s
Copyright © by Pearson Education, Inc.
Publishing as Benjamin Cummings

9. Learning Check
The normal temperature of a chickadee is 105.8°F. What is that temperature on the Celsius scale?
1) 73.8°C
2) 58.8°C
3) 41.0°C

10. Solution 3) 41.0 °C TC = (TF - 32°) 1.8 = (105.8 - 32°)
= ( °)
= 73.8°F = °C
1.8°

11. Learning Check
A pepperoni pizza is baked at 455°F. What temperature is needed on the Celsius scale?
1) 423°C
2) 235°C
3) 221°C

12. Solution
A pepperoni pizza is baked at 455°F. What temperature is needed on the Celsius scale?
2) 235°C
TF - 32° = TC
1.8
( °) = 235°C

13. Learning Check On a cold winter day, the temperature is –15°C.
What is that temperature in °F?
1) 19°F
2) 59°F
3) 5°F

14. Solution 3) 5°F TF = 1.8 TC + 32 TF = 1.8(–15°C) + 32° = – 27 + 32°
= – °
= 5°F
Note: Be sure to use the change sign key on your calculator to enter the minus – sign.
1.8 x 15 +/ – = –27

15. Kelvin Temperature Scale
The Kelvin temperature scale
has 100 units between the freezing and boiling points of water.
100 K = 100°C or 1 K = 1°C
is obtained by adding 273 to the Celsius temperature.
TK = TC
contains the lowest possible temperature, absolute zero (0 K).
0 K = –273°C

16. Temperatures
TABLE 2.5

17. Learning Check What is normal body temperature of 37°C in Kelvins?

18. Solution What is normal body temperature of 37°C in kelvins? 2) 310. K
TK = TC
= 37°C
= K