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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 40C = 40F