Unit 3 Term 1 Flashcards
what is homogeneous equilibrium?
reactions in which all components are in the same phase (liquid, gas, solid)
what is heterogeneous equilibrium?
reactions in which components are in different phases (liquid + solid)
what is dynamic equilibrium?
a state which occurs after a reverse reaction when concentrations and product/reactant ratios become constant and reverse/forward reactions occur at the same rate
what is an open system?
a reaction vessel which does not have a lid, allowing reactants or products to be lost to the atmosphere
what is a closed system?
a reaction vessel that is closed off or has a lid, meaning reactants and products aren’t lost to the atmosphere
what is activation energy?
the minimum amount of energy required in a collision for a reaction to occur
what is enthalpy?
the energy stored within chemical substances, referred to as its chemical or heat content
what is a forward reaction?
the reaction between reactants to form products
what is a reverse reaction?
the backwards reaction in which the products react to reform the reactants
what is Le Châtelier’s Principle?
the theory that a system at equilibrium will adjust to minimise the disturbance to it (equilibrium will shift to oppose change)
which factors impact changes to the equilibrium?
concentration
pressure
temperature
volume
catalysts
what changes result in a net forward reaction?
decrease in product concentration
increase in reactant concentration
what changes result in a net backwards reaction?
increase in reactant concentration
decrease in product concentration
what effect does a catalyst have on a reaction?
it will initially lower the activation energy, before equilibrium is reached faster, however concentrations stay the same so no net reaction occurs.
what is the formula for the equilibrium constant? And what does it exclude?
kc = [products]^p/[reactants]^r
excludes liquids and solids
What do different values for kc mean?
kc>1, then the concentration of products is greater than that of the reactants
kc<1, then the concentration of reactants is greater than that of the products
kc=1 then ratios are equal
How is Q different to kc?
Q is a trial expression, it uses the same equation as kc, however it uses practical values whereas kc uses theoretical values.
What do different values for Q mean?
Q>kc, too far right, system will shift left
Q<kc, too far left, system will shift right
Q=kc system is at equilibrium
What is an organic acid?
they’re carbon based acids such as, lactic, acetic, and citric (COOH) “-oic”
What are some inorganic acids?
- hydrochloric HCL
- carbonic H2CO3
- nitric HNO3
- sulphuric H2SO4
What is the Bronsted-Lowry theory?
- acids are proton donors
- bases are proton acceptors
Describe monoprotic acids
- one proton
HCL => H+ => Cl-
HNO3 => H+ => NO3-
Describe diprotic acids
- two protons
H2SO4 => 2x H+ => SO4^2-
Describe polyprotic acids
- many protons
H3PO4 => 3x H+ => PO4^3-
