Section 5.2 - Thermal Content Flashcards
Define internal energy
Sum of the individual potential and kinetic energies of all molecules within the body
State the first law of thermodynamics
The change of internal energy of the object is equal to the total energy transfer due to work done and heating
Define specific heat capacity
The energy required to change the temperature of 1kg of the substance by 1K without changing state
Describe the experiment to measure the specific heat capacity of a metal
Metal block of known mass in an insulated container. Electrical heater inserted into a hole in the metal, thermometer into another.
Measure the temperature change over a given time
Which measurements are used to measure specific heat capacity of a metal, and how?
Heater's current (I) Heater's pd (V) Time of heating (t) Temperature change (ΔT) mcΔT=IVt (rearrange for c)
State Boyle’s law
When a fixed mass of gas is reduced in volume by a compressing piston, the pressure inside the piston increases
Explain why Boyle’s law is true
Gas particles all in motion Pressure exists from surface collisions exerting a force Volume decreases Collisions occur more frequently Pressure increases
State Charles’ law
For a fixed mass of an ideal gas at constant pressure, its volume is directly proportional to its absolute temperature
State the pressure law
For a fixed mass of an ideal gas at constant volume, its pressure is directly proportional to its absolute temperature
Define Avogadro constant
The number of atoms in exactly 12g of carbon-12
Define molar mass
The mass of 1 mol of the substance
What are the five assumptions that are made for the kinetic theory equation?
Molecules are point molecules No attractive forces between molecules Molecules move in continual random motion All collisions are elastic Time of collisions is negligible
Define molar heat capacity
The energy required to change 1 mol of gas by 1K
Define heat capacity
The energy required by an entire object to change temperature by 1K
