Enriched Chemistry Investigation 12

Two ways for a chemical reaction to end?

1. it goes to completion (all reactants are converted into the product)

2. It reaches equilibrium (where the reactant and product concentrations stop changing even though the reaction has not reached completion)

what is a reversible reaction?

a chemcial reaction that can proceed in both directions

At the beginning of a reaction, what are the concentrations of the reactant and product?

the reactant concentration is high

the product concentration is zero

At the beginning of a reaction, what are the forward and reverse reaction rates?

the foward reaction rate is fast

the reverse reaction rate is zero

As the reaction proceeds the reactions and production concnentration are

The reactant concentration goes down (they are being used)

The product concentration goes up (they are being made)

As the reaction proceeds, the forward and reverse reaction rates

The forward reaction rate will slow down

The reverse reaction rate will speed up

According to collision theory, when a reaction proceeds, the concentration of reactants decreases (because they are being converted into products), so the collision frequency decreases. On the contrary, the reverse reaction will increase because the collision frequency increases.

What is equilibrium?

When the rate of the forward reaction equals the rate of the reverse reaction, and the reaction looks like it has stopped because the concentration of the reactants and products is no longer changing.

What is the abriviation for Equilibrium?

K or K subscrip eq

What does the equilibrium give a sense of?

What does the following single?

K>1

K<1

K=1

The extent of a reaction and its stability.

K>1 the forward reaction the right side, products>reactants at equilibrium

K<1 facors the reverse, reactions< products at euqilibrium facors the left side

K=1 products=reactant at equilibrum

What is Le Châtelier, principal?

when a reaction is at equilibrium if we disutbt it it will shieft to counteract the change and restablish the equilibrium

Châtelier, principal, how can you disturb the reaction? How will it shift?

Disturb it by: changing the concentration, tempertature, volume and prussure

Shift:

left- reverse faster

right- fowards faster

how does a catalyst impact the equilibrium shift

A catalyst does NOT shift the position of the equilibrium or cause the reaction at equilibrium to shift. But it can speed up the forward and reverse reactions

Châtelier's principle when changing the volume + pressure for gases only, what happens?

If the volume decreases, the pressure will increase. The reaction will shift to the side with fewer molecules to try and balance the pressure

If the volume increases, the pressure will decrease. The reaction will shift to the side will more gas molecules to balance out the pressure

How does Endothermic differ from Exothermic?

endothermic:

absorbs heat

increases temp the equilibrium shifts to the right, favoring the products

decreases temp, the equilibrium shifts to the left, favoring reactants

Exothermic:

releasing heat

increasing temperature shifts the equilibrium to the left, favoring reactants

decreasign temp shifts the equilibrium to the right favoring the products