Rate Process In Chemical Reactions Flashcards
What’s a spontaneous reaction?
Rxn that occurs without any further help or input
A spontaneous reaction (which happens on its own) go from what energy state?
A reaction to happen on its own needs to be High energy (unstable) to go to low energy (stable)
What’s a rate limiting step in a chemical reaction?
It is the slowest step in a reaction that delays the rate of overall reaction ie. everything else
What’s equilibrium?
When the rate of forward reaction is same as the rate of reverse reaction
Thermal energy
Heat energy
Thermal energy
When atoms have kinetic energy. Something cold i.e. low thermal energy and something hot i.e. high thermal energy
What are the forces that can cause potential energy?
Potential energy is possesed by an object due to its position and it can be caused by:
- Gravitational forces
- Nuclear forces
- Electromagnetic forces
What happens when an object moves in same direction as force?
Potential energy is released and turned into kinetic energy
What happens when an object moves in opposite direction as force?
Object stores the potential energy
Negative change in energy system
When heat is transferred from system to the surroundings
Positive change in energy system
When heat is transferred from the surrounddings to the systems
Negative change in energy
System expands (work is done by system in surrounding)
Positive change in energy
System compressed (work is done on system by the surrounding)
Net energy equation
Delta U = Heat (q) - work (W)
What’s Enthalpy?
Sum of all the internal energy (kinetic and potential) in the system
Breaking bonds
Requires energy as a molecule is going from stable to unstable
Forming bonds
Releases energy as it goes from unstable to stable
Endothermic reactions cause
Positive enthalpy change as energy is being absorbed and thermal energy of system decreases
Exothermic Reaction
Negative enthalpy change as energy is being released and thermal energy of system increases
Entropy (measure of disorder) is positive when?
System moves towards more disordered state
Entropy (measure of disorder) is negative when?
System moves toward less disordered state
Is it easier for chemical reactions to increase entropy or decrease it?
Increasing entropy is easier as they proceed to be more disordered
What’s Gibbs free energy?
Energy available overall considering the enthalpy and entropy of the system
What’s the equation for Gibbs energy?
🔺G = 🔺H - T🔺S
🔺G < 0: spontaneous rxn in forward direction
🔺G > 0: nonspontaneous rxn in forward direction
🔺G = 0: rxn is at equilibrium
