temperature

Temperature ºF ºC K K = ºC Always use absolute temperature (Kelvin) when working with gases.

Absolute zero The temperature at which there ceases to be any molecular motion (0 K or -273 ° C).

Convert the following numbers from degrees Fahrenheit ( ̊F) to degrees Celsius ( ̊C). Example: 40  F = 8 8 x 5/9 = 4.4  C Convert the following numbers from degrees Celsius to degrees Fahrenheit. Example: 40  C 40 x (9/5) = = 104  F

Convert 25.0 °C to Kelvin = Convert K to °C – 273 = 42 °C

Volume and Temperature

The volume of a gas increases with and increase in temperature.

Charles Law Animation

A plot of V versus T is a straight line. When T is measured in  C, the intercept on the temperature axis is  C. We define absolute zero, 0 K =  C. Note the value of the constant reflects the assumptions: amount of gas and pressure.

Charles’ Law The volume of a gas is directly proportional to the Kelvin temperature if the pressure is held constant. V = K x T(K is some constant) V = K T

Charles’ Law states that the volume of a fixed amount to gas at a constant pressure, is directly proportional to its absolute temperature.

A sample of carbon monoxide gas occupies 3.20 L at C. At what temperature will the gas occupy a volume of 1.54 L if the pressure remains constant? V 1 = 3.20 L T 1 = K V 2 = 1.54 L T 2 = ? T 2 = V 2 x T 1 V1V L x K 3.20 L = = 192 K V 1 /T 1 = V 2 /T 2

Example A gas sample occupies a volume of 1.89 L at 25°C. What would be the volume of the sample at 75°C?

Example A sample of carbon dioxide in a 5.00-L container has a temperature of 56.9°C. At what temperature will this sample of CO 2 occupy a volume of 3.00 L?