HALLO GYS HOW WAS THE CHEMISTRY PAPER? (5070)

[Sharukh khan]

What was the answer of this :
In estrification a catalyst is used which provide H+ ion describe how the catalyst effect the rate of reaction ?

 

[Knightmare11]

H2SO4 as catalyst. H2SO4 is hygroscopic (It absorbs water.)

As an ester is a reversible reaction; i.e - Alcohol + Carboxylic Acid --> <--- Ester + water, the use of H2So4 decreases the amount of water (again, hygroscopic) Therefore, from Le Chatelier's principle, the system reacts so as increase yield of water, so equilibrium shifts to the right, thereby increasing the yield of Ester at equilibrium.



[EDIT]

A catalyst reduces the activation Energy Barrier, thereby increasing rate of reaction due to the frequency of effective collisions occurring at a lower energy level.

 

[thementor]

What was the answer of this :
In estrification a catalyst is used which provide H+ ion describe how the catalyst effect the rate of reaction ?

H2SO4 as catalyst. H2SO4 is hygroscopic (It absorbs water.)

As an ester is a reversible reaction; i.e - Alcohol + Carboxylic Acid --> <--- Ester + water, the use of H2So4 decreases the amount of water (again, hygroscopic) Therefore, from Le Chatelier's principle, the system reacts so as increase yield of water, so equilibrium shifts to the right, thereby increasing the yield of Ester at equilibrium.

Knightmare11 your answer is totally wrong!!
The question said, how does the catalyst affect the rate of the reaction, NOT THE YEILD. A catalyst has no effect on the yield, so writing about the yeild of water will not get you any marks,
The actual answer is:
A catalyst speeds up the rate of the reaction, by lowering the activating energy(the minimum energy needed to allow a reaction to occur).

 

[Knightmare11]

ah misread Lol, but was this in section B?
[EDIT]

A catalyst reduces the activation Energy Barrier, thereby increasing rate of reaction due to the frequency of effective collisions occurring at a lower energy level.

 

[thementor]

ah misread Lol, but was this in section B?
[EDIT]

A catalyst reduces the activation Energy Barrier, thereby increasing rate of reaction due to the frequency of effective collisions occurring at a lower energy level.

LOL nope it was section A Q2

 

[Knightmare11]

Yeah, now I remember , 3rd page?

 

[thementor]

Yeah, now I remember , 3rd page?

yup

 

[Sharukh khan]

Knightmare11 your answer is totally wrong!!
The question said, how does the catalyst affect the rate of the reaction, NOT THE YEILD. A catalyst has no effect on the yield, so writing about the yeild of water will not get you any marks,
The actual answer is:
A catalyst speeds up the rate of the reaction, by lowering the activating energy(the minimum energy needed to allow a reaction to occur).

oh yessssssssss i have also wrtten this but iam confuse weather my answer is correct or the other one

 

[thementor]

oh yessssssssss i have also wrtten this but iam confuse weather my answer is correct or the other one

If you wrote this, then its correct, 2 marks will be awarded

 

[Sharukh khan]

If you wrote this, then its correct, 2 marks will be awarded

DIL KHUSH KAR DIA YAR

 

[dee1234567]

So good |:
What was the product of the reaction NH3 + H2SO4. ( NH4 )2SO4 only? Or water too?

i think its NH4OH + H2SO4 . ITS AQUEOUS AMMONIA...

 

[Knightmare11]

i think its NH4OH + H2SO4 . ITS AQUEOUS AMMONIA...

Nope Aqeous Ammonia is still Nh3(aq), What you wrote is Ammonium Hydroxide.

 

[thementor]

Nope Aqeous Ammonia is still Nh3(aq), What you wrote is Ammonium Hydroxide.

Precisely. And its clearly written in the examiner tips that Ammonium Hydroide is wrong, despite the fact that it is written in many books. It is actually Aquesous Ammonia.

 

[Knightmare11]

Precisely. And its clearly written in the examiner tips that Ammonium Hydroide is wrong, despite the fact that it is written in many books. It is actually Aquesous Ammonia.

Thanks Bro , but are you sure? lol I'm getting doubts ..

 

[thementor]

Guyz, I just wanna confirm that I didint leave out any question
Q1. as usual was selecting different substances
Q2. on hydrocarbons (carboxylic acids)
Q3. (Atomic Structure and Silicon(IV) oxide
Q4.Greenhouse gases etc
Q5.Rate of reaction

Section B
B6.Aluminum extraction etc
B7.Hydrocarbons
I know about B8 AND B9

 

[Knightmare11]

Guyz, I just wanna confirm that I didint leave out any question
Q1. as usual was selecting different substances
Q2. on hydrocarbons (carboxylic acids)
Q3. (Atomic Structure and Silicon(IV) oxide
Q4.Greenhouse gases etc
Q5.Rate of reaction

Section B
B6.Aluminum extraction etc
B7.Hydrocarbons
I know about B8 AND B9

You did not miss anything

 

[thementor]

You did not miss anything

yayyyy thaank GOD!

 

[Sharukh khan]

Guyz, I just wanna confirm that I didint leave out any question
Q1. as usual was selecting different substances
Q2. on hydrocarbons (carboxylic acids)
Q3. (Atomic Structure and Silicon(IV) oxide
Q4.Greenhouse gases etc
Q5.Rate of reaction

Section B
B6.Aluminum extraction etc
B7.Hydrocarbons
I know about B8 AND B9

CAN YOU TELL GREEN HOUSE EFFECT QUESTION?

 

[Knightmare11]

'

CAN YOU TELL GREEN HOUSE EFFECT QUESTION?

Name a greenhouse gas
Answer- Methane. That's all I remember though

 

[Sharukh khan]

'

Name a greenhouse gas
Answer- Methane. That's all I remember though

and what you wrote abou green house effect!