Thermochemistry Flashcards
What is thermodynamics?
Study of heat due to force or force due to heat
What is energy?
Ability to do work or transfer heat
What is thermochemistry?
Study of energy and heat associated with chemical reactions and of physical transformations
What is heat?
Energy used to cause increase in temperature
What is work?
Energy used to cause one object that has mass to move.
What is the equation for work?
Work = force * distance
What is a system?
What is a surrounding?
Part of universe which undergoes thermodynamic study.
Everything else
What is an open, isolated, and closed system?
Open- matter and energy can be exchanged to surrounding
Isolated- Neither matter nor heat can be exchanged with surrounding
Closed- Exchange energy not matter with surrounding
What is internal energy? What is the equation?
Sum of a system, is sum of all kinetic and potential energies within system
E.E. = Efinal-Einitial
What is enthalpy change?
Difference in energy between the reactants and products is the amount of heat energy transferred to surroundings.
What is enthalpy?
Heat content of a substance at a constant temperature
What is the equation for enthalpy?
H = internal energy + (pressure)(volume)
What is Heat Capacity?
Amount of heat it takes to raise something by 1 degrees celsius
What is specific heat capacity?
Amount of heat it takes to raise 1 gram of a substance by 1 degrees Celsius
What is the calculation for heat gained?
q or h = (Mass)(Specific Heat Capacity)(Change in temperature)
What is the equation for the change in temperature?
Change in Temperature = Final Temp - Initial Temp
What is a catalyst?
Substance that causes reaction to go faster by reducing activation energy but without being consumed.
What is the equation for heat enthalpy change?
Heat enthalpy change = (-mass)(specific heat capacity)(change in temperature)
How do you calculate total mass?
Total volume * Density
What are the energy laws?
- Energy is neither created nor destroyed
- Entropy (disorder) of the universe is always increasing
- Perfectly crystalline solid at absolute zero has an entropy of zero.
What is Gibbs Free Energy and what is equation?
Tells us about spontaneity of a process
Gibbs Free Energy = Change in Enthalpy - (temperature * change in entropy)
How to convert Celsius to Kelvin?
Kelvin = Celsius + 273.15
Based on Hess’s law, how do you find the change in enthalpy?
Change in enthalpy = Sum of standard heats of products - sum of standard heats of reactions
