Ch. 1 Equilibrium Flashcards
What 5 factors effect rate of reaction
concentration, pressure, temperature, sa, catalyst
What is activation energy
difference in enthalpy between reactants and activation complex)
chemical systems reach equilibrium when:
closed system
involves a reverse reaction
AT equibliurm, what occurs
o Rate of forward reaction= rate of reverse
o Concentrations remain constant
o macroscopic properties= constant
what are the two ways equilbiurm can be graphed
o Reaction rate and time
o Concentration and time
What does the graph for reaction rate look like
- forward high
- reverse at 0
- will become equal
What does the graph for concentration look like
- reactants high
- products on zero
- will plateau
what is the formala for equilibrium expression
[reactants] power of coefficients
difference in what is included in equilibrium constants for heterogeneous and homogenous system
- In heterogeneous system:
o Only include gases and solutions (not solids and liquids as their concentrations do not vary) - In homogenous system:
o Include solids and liquids as proportions are important
What is the effect of temp on equilibrium constant
- Change in temperature > change in proportion of particles to collide
- Extent of these changes relative to each other determine amount of substances, and therefore effects equilibrium constant
what does a large and small K value mean
o Large K value= reaction favours forward (large product amount)
o Small K value= reaction favours reverse (small product amount)
o K close to 1= significant amount of both
if volume halved…
pressure doubles
if volume changes by adding water, what happens
- If volume changes by adding water, same principal as concentration of aqueous substances change
o Concentration decreases
o Rate of reaction that uses greater proportion of aqueous molecules will decrease most = this reaction slowly increases while opposite decreases
What is endothermic
products have more enthalpy (energy absorbed from surroundings)
what is exothermic
reactants have more enthalpy (energy released to surroundings)
what occurs when temp increases
- both forward and reverse reaction increases
o However exothermic will increase more due to high activation energy
what reaction is favoured for increase in temp and decrease
- Temp increase= endo favoured
* Temp decrease= exo favoured
According to le chateleris, what happens for increase in concentration
sudden increase in one substance
According to le chateleris, what happens for increase in volume/ decrease pressure
sudden decrease in all gases
According to le chateleris, what happens for increase in temp
no sudden changes
