Thermodynamics Flashcards
What is a surrounding?
Everything outside the system.
What is a system?
The part of a system we want to study. A reaction mixture.
What is an open system?
A system that can exchange both energy and matter with the surrounding.
What is a closed system?
A system that can only exchange energy with the surrounding.
What is an isolated system?
A system that can exchange neither energy nor matter with the surrounding.
What is thermochemistry?
Study of energy changes as matter undergoes physical, chemical or nuclear transformations.
What is energy?
The ability to do work.
What is kinetic energy?
Energy due to motion.
What is potential energy?
Energy due to position or stored energy.
What is thermal energy?
Total potential and kinetic energy a sample of matter has.
What is temperature?
Measure of average kinetic energy.
When kinetic energy increase, the motion of particles increase and thus the temperature increases.
What is heat?
Energy transformed from one substance to another due to temperature difference between them.
What is heat represented by and measured in?
Q
Measured in joules or kilojoules.
What is the formula to calculate heat?
Q = mct
What is the law of conservation of energy?
Energy cannot be created or destroyed.
What is specific heat capacity?
Amount of heat required to raise the temperature of 1 gram of a substance by 1*C.
What is specific heat capacity measured in?
J/g*C
KJ/g*C
What is molar heat capacity?
Specific heat capacity X molar mass
What is calorimetry?
The experimental technique used to obtain information to calculate heat.
What is enthalpy?
The amount of energy gained or lost when reactants form products. Represented by
What is molar enthalpy?
The amount of heat gained or lost per mole of a substance during a reaction formula.
What is the formula for molar enthalpy? What are the units?
Delta H = q/n
KJ/mol
What is an exothermic reaction?
When their is a loss of heat from the system to the surrounding. Temperature increases. Negative molar enthalpy
What is an endothermic reaction?
A gain of heat energy from the surrounding to the system. Temperature decreases. Positive molar enthalpy
Which process is bond making?
Exothermic
Which process is bond breaking?
Endothermic
What is Hess’ Law?
The sum of the enthalpies of the steps of a reaction will equal the enthalpy of the overall reaction.
What is standard enthalpies of formation?
The amount of heat lost or gained when one mole of a substance is made from its elements in their standard state.
