Introduction Thermodynamics

Thermo It is hot Measure of HEAT.  form of energy  depends on amount of matter  total vs. It is cold the same thing!!! VS. TEMPERATURE  measurement of heat energy  doesn’t depend on amt. of matter  average Heat dynamics Changes Presence of heat energy Absence of heat energy

Calorimeter  Joules (J): metric unit of heat E  H 2 O: 1g  raise 1°C Measures energy changes 25°C26°C How much heat is needed? 4.18J = 1 cal Aluminum: 1 g  raise 1°C  0.903J SPECIFIC HEAT CAPACITY (c) the amount of heat needed to raise the temperature of 1g of a substance by 1°C.

Heat Calculations LL aw of Conservation of Energy heat lost = heat gained HH eat flows from warmer to cooler areas.  E = m ∙ c ∙  T Change in energy: heat lost or gained Specific heat capacity Mass (g) of substance Change in temperature: T f - T i

Ex 1: How much heat is lost when an aluminum block with mass of 4110g cools from 660°C to 25°C? m TiTi TfTf C al =  E = m ∙ c ∙  T

 2,400,000 J lost

Ex 2: If a sample with a mass of 23.10g changes temperature from 35.0°C to 50.0°C by absorbing 457.0J of energy, what is the specific heat? m TiTi TfTf E