physical chemistry Flashcards
Force
Rate of change of momentum . A force is a directed push used to accelerate a body . F=m*a( Newton’s second law of motion)
Work
ForceDistance=Work
Work is done when an object is moved against an opposing force . The units for measuring Work are Nm or Joules(J). Work is the change in energy .
Energy
Energy is the capacity to do work .It is measured in Joules (J)
Kinetic energy
Energy of a body due to its motion. Ek=1/2mv^2
Potential energy
Energy of a body due to its position and the force acting on it. ( hen the force is gravity then Ep=mgh)
Total energy
Total energy of a system is the sum of potential and kinetic energy . Ek+Ep=E
Law of conservation of energy
Energy cannot be destroyed or created. It can only be changed from one form to another.
Pressure
Pressure is the force exerted over a defined area. P=F/A. The unit of pressure is Pascal , Pa.
Work formulas
W= Force*Distance
W=Pressure * change in volume
Heat
Heat is the transfer of energy as a result of the motion of particles. It is a form of energy.
Temperature
Measure of the average kinetic energy of particles . It determines the flow of heat when in contact with another object.
Conversion between Celsius and Kelvin
K= C+273.15
C= K-273.15
Molar concentration
Amount of mol/Per volume of solution
-mol/V
Molality
Amount of Mol/Per mass of solvent
-mol/m
Why is Molality a better way of quantifying amount of substance compared to Molarity
Molality is better way of quantifying an amount of substance because volume changes drastically with temperature changes compared to the mass . Molality is a more constant measure of concentration when temperature changes are involved.
