Honors Chemistry
Unit I - Power Point 6
Temperature Conversions
Sections 1.7
Temperature Scales
Three Systems for Measuring Temperature
• Fahrenheit
• Celsius
Gabriel Fahrenheit
• Kelvin
1686-1736
Anders Celsius
1701-1744
Lord Kelvin
(William Thomson)
1824-1907
The Three Major Temperature
Scales
Notice that 1 kelvin = 1 degree Celsius
Converting Between Scales
TK  TC + 273.15


5C
TC  TF  32 F
9F
TC  TK  273.15
9F
TF  TC 
+ 32 F
5C
Calculations Using
Temperature
• Generally require temp’s in kelvins
• T (K) = t (˚C) + 273.15
• Body temp = 37 ˚C + 273 = 310 K
Temperature Conversions
A person with hypothermia has a body
temperature of 29.1°C. What is the body
temperature in °F?
°F
=
9/5 (29.1°C) + 32
=
52.4 + 32
=
84.4°F
Learning Check
The normal temperature of a chickadee is
105.8°F. What is that temperature in °C?
1) 73.8 °C
2) 58.8 °C
3) 41.0 °C
Answer: 41 °C
Learning Check
Pizza is baked at 235 °C . What is that in °F?
1) 455 °f
2) 350°C
3) 400°C
Answer: 455 °F
Exercise
At what temperature does C = F?
Solution
•
•
Since °C equals °F, they both should be the same
value (designated as variable x).
Use one of the conversion equations such as:


5C
TC  TF  32 F
9F
•
Substitute in the value of x for both TC and TF.
Solve for x.
Solution
TC 

x 

x 
 40
TF  32 F
x  32 F

5C
9 F

5 C
9 F
So  40C =  40F