The Student Room Group

ocr f321 f322 questions and answers revision

Scroll to see replies

Reply 40
Original post by Rainingshame
You missed off the +2H2o at the end, that's 2 marks lost. And also you forgot the second part it's acidified potassium dichromate. The catalyst is h2SO4.
got a question on unit 2 for me?

oh now i put them i did not see the question with potassium one??????
Original post by PrincessMedic
Explain the trends in ionisation energy and atomic radius across a period. (3 marks)


-Electron shield is equal.
-Positive charge of nucleus causing attraction of electrons increases.
- So the amount of energy to remove an electron increases and the electrons are pulled further in reducing atomic radius.
Reply 42
Original post by Natalie21
No idea - never learnt this.

it is in the book last page its for toothpaste
Original post by otrivine
oh now i put them i did not see the question with potassium one??????


it was attached to the end of the equation question.
Original post by otrivine
it is in the book last page its for toothpaste


i was gonna say that, but it's not in the last page of the official one.
Reply 45
Original post by Rainingshame
i was gonna say that, but it's not in the last page of the official one.


can u give me one more unit 2 cause i cant be making mistakes then i will give u 2 please
Original post by otrivine
can u give me one more unit 2 cause i cant be making mistakes then i will give u 2 please


Q.
a) define a heterogeneous catalyst
b) Explain the way that it works (hint: catalystic converter).
c) Describe and explain a catalysts impact on the composition of an equilibrium mixture.

I should become a tutor, i'm good at making these questions up :smile:
Reply 47
Original post by Rainingshame
Q.
a) define a heterogeneous catalyst
b) Explain the way that it works (hint: catalystic converter).
c) Describe and explain a catalysts impact on the composition of an equilibrium mixture.

I should become a tutor, i'm good at making these questions up :smile:


thanks
1) form of catalysis where the phase of the catalyst differs from that of the reactants. Phase here refers not only to solid, liquid, vs gas, but also immiscible liquids, e.g. oil
2) adsorption weakning of bonds and desorption
3)catalysts will have no affect on rate of equation as a catalyst only helps to speed up the reaction both directions.
Original post by otrivine
thanks
1) form of catalysis where the phase of the catalyst differs from that of the reactants. Phase here refers not only to solid, liquid, vs gas, but also immiscible liquids, e.g. oil
2) adsorption weakning of bonds and desorption
3)catalysts will have no affect on rate of equation as a catalyst only helps to speed up the reaction both directions.


DING!DING!DING correct! :biggrin:
Original post by Rainingshame
Q.
a) define a heterogeneous catalyst



Swear this isnt in the spec?
Reply 50
Original post by Rainingshame
DING!DING!DING correct! :biggrin:


good now im happy :wink: ok describe how margarine is made(2)

why should biofuels be used than fossil fuels (3)
Original post by otrivine
good now im happy :wink: ok describe how margarine is made(2)

why should biofuels be used than fossil fuels (3)


1. Hydrogenation of alkenes to alkanes. Using Nickel and 150oC.

2. Renweable source of energy. Means we are less reliant on fossil fuels which are non-renewable and are a scarce source. Biofuels are technically "carbon neutral" as the plants fix Co2 during growth - hence combustion of biofuels does not contribute to global warming. (Although energy is required to process, harvest and distribute the fuel so it is not completely carbon neutral).
Reply 52
Original post by Natalie21
1. Hydrogenation of alkenes to alkanes. Using Nickel and 150oC.

2. Renweable source of energy. Means we are less reliant on fossil fuels which are non-renewable and are a scarce source. Biofuels are technically "carbon neutral" as the plants fix Co2 during growth - hence combustion of biofuels does not contribute to global warming. (Although energy is required to process, harvest and distribute the fuel so it is not completely carbon neutral).


excellent
Original post by Natalie21
Swear this isnt in the spec?


I keep going through this thread and seeing things and thinking 'we didn't learn this' or 'I'm sure that question's wrong' and you point them out. Glad I'm not the only one thinking those thoughts

*Goes back to lurking :ninja:*
Original post by Natalie21
Swear this isnt in the spec?


It is, it was in one of the past papers as well. OCR A? for the heinsmenn textbook it's page 206/207.
Reply 55
Original post by Rainingshame
It is, it was in one of the past papers as well. OCR A? for the heinsmenn textbook it's page 206/207.

hi can u ask me questions please
Original post by DarkAndTwisty
I keep going through this thread and seeing things and thinking 'we didn't learn this' or 'I'm sure that question's wrong' and you point them out. Glad I'm not the only one thinking those thoughts

*Goes back to lurking :ninja:*


Hahaha I'm very glad I'm not too!

Join in with the thread :smile:

Original post by Rainingshame
It is, it was in one of the past papers as well. OCR A? for the heinsmenn textbook it's page 206/207.


It is in the textbook but its not in the specification - hence why my school hasn't taught it - they always say there is lots of irrelevant info in the textbook.
The fact that I actually bought it wound the chemistry department up!
Which past paper?
Reply 57
Original post by Natalie21
Hahaha I'm very glad I'm not too!

Join in with the thread :smile:



It is in the textbook but its not in the specification - hence why my school hasn't taught it - they always say there is lots of irrelevant info in the textbook.
The fact that I actually bought it wound the chemistry department up!
Which past paper?

hi what happened lets ask questions it was ur turn :biggrin:
Original post by otrivine
hi what happened lets ask questions it was ur turn :biggrin:


I went out sorry.

Okay:

How many electrons can fit in the 3f sub-shell?
Reply 59
Original post by Natalie21
I went out sorry.

Okay:

How many electrons can fit in the 3f sub-shell?

but wait f is not part of our syllabus though

Quick Reply

Latest