Unit 4: Equilibrium and chemical systems

graphing, math, and mixture of unit 3 rates of reaction

Conditions for an equilibrium system

• a closed system (energy ONLY leaves or enters NOT MATTER)

• reversible reaction (both forward and reverse direction)

• reactants and products are present at the same time (rates of the forward and reverse reactions must be equal)

• equations use this symbol “⇌”

• Solubility Equilibrium—> balance b/tw solid and ions

• Phase Equilibrium—> balance b/tw 2 states of a substance

Analyzing graphs

• on the graph, there is a constant period (reached Chemical Equilibrium)

• the constant period is shown by the straight line/Plateau (concentration of react. and prod. will NOT CHANGE)

• reactants never COMPLETELY “disappear”

• Position of Equilibrium—> on the graph, it is the point where the formation of react. or prod. is favored (concentration is higher than the other)

Equilibrium Law and constant

• uses stoichiometric coefficients= exponents

• “K”—> defines the equilibrium law (CONSTANT and NO UNITS)

• K is constant UNLESS temp. change

• Heterogenous Equilibrium—> react. and prod. are present in 2 differ states (NOT INCLUDED in the EXPRESSION for the system)

‘K” in more depth

• K<1—> more react. are present

• K=1—> 50/50

• K>1—> more prod. are present

• Kforward and Kreverse are INVERSLY related