Temperature

Temperature Scales

• Temperature can be measured with a variety of scales:– Celsius scale– Fahrenheit scale– Kelvin scale

Comparison of Temperature ScalesCelsius Scale Fahrenheit Scale Kelvin Scale

Boiling point of water

100C 212F 373 K

Freezing point of water

0C 32F 273 K

Absolute Zero -273C -460F 0 K

• The Celsius scale is used in Canada and Europe.• The Fahrenheit scale is used in the United States & the UK.• The Kelvin scale is used by scientists.

Absolute Zero

• In Kelvin, it is equal to 0 K.• In Celsius, it is equal to -273C• Is the lowest possible temperature• Experiments have shown that matter cannot

be cooled to temperatures lower than absolute zero.

• At absolute zero there is absolutely no movement of matter.

Temperature Conversion Formulas

• Celsius can be converted to Fahrenheit• The formula is:

F = 1.8 (C) + 32

• Convert 37 C into F

F = 1.8 (C) + 32

• Convert 37 C into F

F = 1.8 (37C) + 32F = 66.6 + 32

F = 98.6

Significant figures! How many do we keep? 2!97 F

Temperature Conversion Formulas

• Fahrenheit can be converted to Celsius• The formula is:

C = F - 32 1.8

• Convert 75.3 F into C

C = F - 32 1.8

• Convert 75.3 F into C C = F - 32 C = 75.3- 32 C = 43.3

1.8 1.8 1.8

C = 24.055

Significant figures! How many do we keep? 3!24.1C

• Celsius can be converted to Kelvin• The formula is:

C + 273 = K

• Convert 85.15C into K• Convert 255 K into C

Temperature Conversion Formulas

C + 273 = K

• Convert 85.15C into K

C + 273 = K85.15 + 273 = K

358 K

Significant figures! How many do we keep? 2 decimal places!

358.15C

C + 273 = K

• Convert 255 K into C

C + 273 = KC + 273 = 255

-273 -273C = -18

Significant figures! How many do we keep? 0 decimal places!

-18C

Temperature Conversion Formulas

• To convert from Fahrenheit to Kelvin you must convert Fahrenheit to Celsius AND then convert Celsius to Kelvin!

• Convert 64.9F into K

C = F - 32 and C + 273 = K 1.8

• Convert 64.9F into K

• First, convert F into C

C = F - 32 C = 64.9 - 32 C = 32.9 1.8 1.8 1.8

C = 18.277

C = F - 32 and C + 273 = K 1.8• Second, convert C into K• C = 18.277

C + 273 = K18.277 + 273 = K

291.277 K

Significant figures! How many do we keep? 3!291 K