ocr a f325 revision thread

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You are completely right, and thanks alot for writing that.

I need to keep that in mind.

I got the best in my class and everyone else got D's or below. But I need to remember on every exam I'm competing against other Students who are very good.

I think my technique was poor, I usedwrote memorization instead of proper learning.

This time I will
1. Make Question Sheets for Each Module
2. Then do Practice and Exam Style Questions
3. THen only once I've finished 1. and 2 for all Modules I will do full past papers.

Last time I had seen all the past papers so I had nothing to practice with.

Thanks again for writing that and putting things into perspective for me. It will help me alot.

No problem. Well those plans sound good, hope the effort pays off for you.

Reply 121

tom2013

Original post by krazie.x

Anyone got f325 jan 2013 mark scheme please?

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i can get it

Reply 122

otrivine

Original post by tom2013

i can get it

yes please, that would be great :smile:

Reply 123

krazie.x

Original post by tom2013

i can get it

Please do, would be greatly appreciated

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Reply 124

Alotties

I totally forgot that I'm resitting this exam! :s-smilie:

I scraped an E in the Jan exam and I need a B overall.
I'm also resitting F322 (got a high D) as well as sitting F324.
I got a B in F321 and an A in F323. I'm hoping for another A in F326.
I've finished learning F324 but haven't started much revision (I've done a few practice questions and I have a past paper to look at). I'm half way through redoing F322 (I'm pretty confident that I can do well in F322) and I have yet to start F325, I don't even know where to begin :frown:

I was pretty strong on rates, Kc and anything to do with calculations and my weak areas were fuel cells and electrode potentials (which came up a ton on the Jan exam after I didn't bother to learn much about them).

(edited 11 years ago)

Reply 125

MathsNerd1

Original post by otrivine

yes please, that would be great :smile:

Lets go!

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Reply 126

otrivine

Original post by MathsNerd1

Lets go!

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State how to measure initial rate of reaction (2)

Reply 127

MathsNerd1

Original post by otrivine

State how to measure initial rate of reaction (2)

It can be measured by measuring the change in concentration of a reactant or product over a specific time interval. Surely the initial will just be the change in concentration of the reactants?

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Reply 128

otrivine

Original post by MathsNerd1

Not quite , try one more time

Reply 129

MathsNerd1

Original post by otrivine

Not quite , try one more time

Hmm well the definition for it is the change in concentration of a reactant or product per unit time at the start of the reaction when your time = 0

Wouldn't it be just be the concentration of the reactant/product before the reaction has started? If not then I don't know :-/

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Reply 130

otrivine

Original post by MathsNerd1

You would get 1 Mark , the other Mark is for stating to draw a tangent to curve and measure gradient.

My turn

Reply 131

MathsNerd1

Original post by otrivine

You would get 1 Mark , the other Mark is for stating to draw a tangent to curve and measure gradient.

My turn

Oh okay, that would make sense aswell and okay, we'll start easy then build it up.

How do changes in temperature affect the equilibrium constant? (4)

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Reply 132

otrivine

Original post by MathsNerd1

Oh okay, that would make sense aswell and okay, we'll start easy then build it up.

How do changes in temperature affect the equilibrium constant? (4)

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Kc is affected by temperature only. If forward reaction Is endothermic and Kc value increases then equilibrium favours the forward reaction.if the reaction is exothermic in forwrad reaction and Kc value is small then temperature favours reverse reaction.

(edited 11 years ago)

Reply 133

MathsNerd1

Original post by otrivine

Kc is affected by temperature only. If forward reaction Is endothermic and Kc value increases then equilibrium favours the forward reaction.if the reaction is exothermic in backward reaction and Kc value is small then temperature favours reverse reaction.

Correct!

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Reply 134

otrivine

Original post by MathsNerd1

Correct!

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A solution of KOH has concentration of 0.050mol dm^-3. What is the PH? (3)

Reply 135

MathsNerd1

Original post by otrivine

A solution of KOH has concentration of 0.050mol dm^-3. What is the PH? (3)

If the concentration is 0.050 then the value of pOH is 1.30 (3sf)

To find pH you do 14 - pOH
So 14-1.30 = 12.70

pH = 12.70

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Reply 136

IQ Test

Resitting as well, the January paper was murder and it's the only exam I've ever had to resit D:

Reply 137

otrivine

Original post by MathsNerd1

If the concentration is 0.050 then the value of pOH is 1.30 (3sf)

To find pH you do 14 - pOH
So 14-1.30 = 12.70

pH = 12.70

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Excellent!

My turn :smile:

Reply 138

otrivine

Original post by IQ Test

Resitting as well, the January paper was murder and it's the only exam I've ever had to resit D:

Want to revise with me and MathsNerd :biggrin:

Reply 139

MathsNerd1

Original post by otrivine

Excellent!

My turn :smile:

Okay, identify the acid base pairs in the acid base equilibria:
CH3COOH + H2O ------> CH3COO- + H3O+

CH3COOH + HCL ---> CH3COOH2- + Cl-

Write the full and ionic equations for the following acid-base reactions:
Hydrochloric acid and solid calcium carbonate
Nitric acid and magnesium oxide
Ethanoic acid and aqueous calcium hydroxide (7)

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