SC12 & SC15 Flashcards
What is a reversible reaction?
a reaction in which the products can easily be
changed back to the reactants
What is Dynamic equilibrium
A dynamic equilibrium is one where two opposing processes
take place at the same rate
What are some Characteristics of dynamic equilibrium?
- Concentrations/amounts of reactants and products
remain unchanged/constant (though not
necessarily equal) - Rate of forward reaction = rate of backward
reaction
What are some factors affecting the position of equilibrium?
- Temperature
- Concentration
- Pressure – for gaseous reactions
Why does rate change when changing factors in a equation?
The factors affecting the position of equilibrium can change the frequency of the collisions (concentration,
pressure) or the energy and frequency of the collisions (temperature) which brings about a change in the rate of
the reaction affected
What does endothermic mean?
Endothermic reaction: one that takes in energy
What does exothermic mean?
Exothermic reaction: one that gives out energy
In which reactions does pressure affects the equilibrium position?
- Reaction involves only gases
- Reaction involves a change in the number of molecules
What is the effect of a catalyst on a reaction?
- Adding a catalyst increases the rate of both the forward and the backward
reaction to the same extend - Thus, there is no change on the position of the equilibrium
- The equilibrium is only reached faster
Which side does increasing the pressure favour and why?
Increasing the pressure favours the side with the fewer gaseous particles.
In what situation would the Equilibria not affected by pressure changes?
In the above case there are the same number of gaseous particles on both
sides of the equilibrium, so no shift
Which side does decreasing the pressure favor and why?
Decreasing the pressure favours the side with the more gaseous particles.
State All the Equilibria rules. (9)
Equilibria RULES
* ↑ temperature favours ENDOTHERMIC side
* ↓ temperature favours EXOTHERMIC side
* ↑ pressure favours side with FEWEST GASEOUS particles
* ↓ pressure favours side with MOST GASEOUS particles
* ↑ concentration of reactants favours forward reaction
* ↓ concentration of reactants favours backward reaction
* ↑ concentration of products favours backward reaction
* ↓ concentration of products favours forward reaction
* Adding a catalyst has NO EFFECT on equilibrium position
What are the operating conditions for the Haber proccess?
-450 oC temperature
-200 atmospheres pressure
-Iron catalyst
What are the two types of fertilizers and what are their uses?
- They may be natural (e.g manure) or artificial
- They provide nitrogen, phosphorus and potassium as soluble
compounds as root hair cells only absorb mineral ions that are
dissolved in water
