Reversible Reactions + Dynamic Equilibria Flashcards
What can reversible reactions do that normal reactions can’t?
Well, all reactions can turn reactants into products, but reversible reactions can also turn the products back into reactants
Give an example of a non reversible reaction
Magnesium + oxygen -> magnesium oxide
In a symbol equation, what’s different for a reversible reaction compared to a normal one
If it’s reversible, we’ll use a specific kind of arrow (the two way one: ⇌), and if it’s not, we’ll use a normal arrow
Give an example of a reversible reaction?
Nitrogen + hydrogen ⇌ ammonia
What happens after some time after a reversible reaction starts?
Both the forwards and the backwards reaction will happen at the same rate. When this happens, the reaction is in equilibrium
What happens to the reactants as a reversible reaction happens (no dynamic equilibrium). Why does this happen?
As reactants go through reactions, their concentration falls so the forward reaction will slow down. This happens cause reactants are being turned into products so conc. decreases. It’s slow because high conc. means high rate and low conc. means low rate.
What’s the forwards reaction of a reversible?
The forwards reaction is the ordinary one that all reactions can do- reactants to products
What happens to the products as a reversible reaction goes on (no dynamic equilibrium)
More products are being made as the conc. of reactants decrease. And because of this products conc. rises and backward reaction speeds up. This happens because the backwards reaction occurs at the same time as the forward.
What happens to the products and reactants when the reaction is in equilibrium? Why does it look like the reaction stopped.
Both reactions are still happening, they’re still going on, but there is no overall affect happening. No products seem to be being made and no reactants seem to be being used up. In reality, it looks like it stopped because the conc. of products and reactants have reached a balance– they’re constant. So when reactants are used up with the forward reaction, the backward reaction turns them back at the same rate. So it looks like nothing happened.
What is the condition with the system that must be true for dynamic equilibrium to be achieved. Explain the condition.
Dynamic equilibrium is only reached if the reaction happens in a closed system. A closed system is where no matter can enter or exit the reaction. However, since energy is not matter, it can still be transferred in and out.
Dynamic equilibria have three definitive properties. What are they?
They must happen in a closed system (no matter in or out, yes energy in and out)
The forwards and backwards reactions must be happening at the same rate
The conc. of products and reactants have to remain constant (reach a balance)
What does position of equilibrium mean? What’s a common misconception.
When a reversible reaction is in equilibrium, it doesn’t necessarily mean that amount of reactants and products are EQUAL, it just means that they’re constant, they remain the same. So position of equilibrium is where the equilibrium leans (it can be different depending on if there are more products than reactants or vice versa)
What does it mean if the equilibrium lies to the right?
The amount/concentration of products is greater than that of the reactants
What does it mean if the equilibrium lies to the left?
The amount/concentration of the reactants are greater than that of the products
Which way equilibrium lies, depend on conditions. What are they?
Temperature
Pressure (gas)
Concentration (of products and reactants)
