Is my teacher wrong again??? (1 Viewer)

[countrydude]

gday,

The other day my teacher told us that a catalyst has no affect at all on an equilibrium reaction.

But in my text book it says otherwise.

Is he wrong or what??

thanks

 

[kini mini]

Your teacher's English is horrendous - I suspect he understands the situation but is inarticulate. What he means to say is that a catalyst has no effect on the position of the equilibrium. The equilibrium position will simply be achieved more quickly.

 

[SoFTuaRiaL]

kini mini's right. usually, the catalyst gets involved in the reaction but is reproduced in the final stage ..... as a result, the catalyst does not effect, i mean, affect the finished product of a reaction, but instead reduces the activation energy of the reaction which results in the reaction taking place at a faster rate

 

[Twintip]

Originally posted by Da Monstar
usually, the catalyst gets involved in the reaction but is reproduced in the final stage .....

Is that true? I always thought the way a catalyst accelerated a reaction was by creating a surface area (or similar) for the reaction to take place on (and not being involved in the actual reaction at all). Learn something new every day!

 

[spice girl]

To generalise, a catalyst provides an alternate mechanism for the reaction to take place. The new pathway has a lower activation energy, and since more molecules are going to have enough energy to react in this pathway, the reaction SPEED will increase.

The equilibrium position won't change because the catalyst increases the speed of both forward and backward reactions.

 

[spice girl]

Btw, I just realised,

They all say in the books that conc H2SO4 is a catalyst for the esterification reaction. In actual fact, H2SO4 absorbs the water produced, driving the reaction to the right. It affects the equilibrium position! How can it be simply a catalyst?

 

[kini mini]

Originally posted by spice girl
Btw, I just realised,

They all say in the books that conc H2SO4 is a catalyst for the esterification reaction. In actual fact, H2SO4 absorbs the water produced, driving the reaction to the right. It affects the equilibrium position! How can it be simply a catalyst?

It doesn't affect the equilibrium position does it? I don't remember the exact equation you are referring to, but I think that the role H2SO4 plays here is to absorb the product so that the system tries to regain equilibrium and more ester & water are produced. It's like how the Haber process works.

 

[Twintip]

Originally posted by spice girl
To generalise, a catalyst provides an alternate mechanism for the reaction to take place. The new pathway has a lower activation energy, and since more molecules are going to have enough energy to react in this pathway, the reaction SPEED will increase.

Yep, knew that, thanks. I just didn't know that the catalyst itself became involved in the reaction. Actually don't worry I'm crap at trying to explain what I think haha.

 

[mannnnndy]

Originally posted by spice girl
Btw, I just realised,

They all say in the books that conc H2SO4 is a catalyst for the esterification reaction. In actual fact, H2SO4 absorbs the water produced, driving the reaction to the right. It affects the equilibrium position! How can it be simply a catalyst?

I think H2SO4 is one of those 'special' ones where it is both a catalyst and a dehydrating agent.