MCAT Chem Phys

ΔU

change in internal energy

Q

heat added to the system

W

Work done on the system

Equations for Work

W = Fd

Generally going to be mgh

W = -PΔV

Heat Definition

Energy transferred due to temperature difference

Temperature Definition

Average Kinetic Energy of Particles

Conduction

heat transfer through direct molecular collisons

Convection

heat transfer through movement of matter, such as fluids or gases

Radiation

heat transfer through electromagnetic waves/photons

Charge of Proton and Electron

Proton: +1.6 × 10^-19 C

Electron: -1.6 × 10^-19 C

Electric Field Definition (four things to know)

area around the charge where another charge would feel a force

Direction = direction a positive charge would move

Density of Lines = strength of the field

More crowded field lines mean a stronger electric field

Electrostatic Force Equation

F = kq₁q₂ / r²

Electric Field Equation

E = Kq₁/r²

Electric Potential Energy Equation

U = kq₁q₂ / r

Electric Potential Equation

V = Kq₁/r

Units for force, electric field, potential energy, and voltage

Force = N

Electric Field = N/C

Electric Potential Energy = J

Electric Potential V = J/C

First Law of Thermodynamics

ΔU = +Q_in-Q_out+W_on-W_by

Important Battery Information

Positive end (cathode) has higher reduction potential

Negative end (anode) has lower reduction potential

“Pull on electrons” = Chemical potential energy

Reduction Potential Equation

E^ocell = E^ocathode - E^oanode

Work Function Photons

W = Ephoton-KEmax