6P- Chemical Equilibria Flashcards
What happens during a reversible reaction at equilibrium
Forward and reverse reactions proceed at equal rates, concentration of reactants and products remain constant
What’s le châteliers principal
If a system at equilibrium is disturbed, equilibrium shifts to oppose the change
Le châteliers principal can predict the effects of what changes on equilibrium
Temperature, pressure, concentration,
What doesn’t effect the position of equilibrium
Catalysts
What happens to equilibrium when temperature increases
Shifts in the endothermic direction, +ve change in enthalpy, counteract the change
What happens to equilibrium when pressure is increased
Equilibrium shifts to the side with the least moles of gas, to counteract the change
What happens to equilibrium when concentration of reactants increases
Equilibrium shifts to direction of products to counter act change
What’s a homogenous reaction
All reactants and products are in the same state
Why is a compromised temperature used in a reversible reaction for industrial processes
Good yield for reactions which are exothermic in forward direction
Less energy needed so cheaper
Why is a compromised pressure used in reversible reactions for industrial processes
Lowers the cost, high pressure equipment is expensive
Can give higher yield if there are less moles on product side
Expression for equilibrium constant (Kc)
Kc=. (Concentration of products)^ moles/ (concentration of reactants)^moles
How to calculate units of Kc expression
Moles of products - moles of reactants
Multiply number by mol dm^-3
What is equilibrium constant not effected by
Change in concentration
Catalyst
