ocr a f325 revision thread

Original post by otrivine

Oh no

correct! my turn

It's fine cause if we do this at least 2 hours a day thing and just keep alternating then that'll be some great revision for me, but unit 1 is first so I need to focus more on that right now :smile:

Okay:
Explain the properties of transition metal compounds (4)
Also define a transition element (1)

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Reply 162

Original post by MathsNerd1

It's fine cause if we do this at least 2 hours a day thing and just keep alternating then that'll be some great revision for me, but unit 1 is first so I need to focus more on that right now :smile:

Okay:
Explain the properties of transition metal compounds (4)
Also define a transition element (1)

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sure!

1) catalysts, coloured compounds, variable oxidation states and are metals which are hard. Have partially filled d sub shells

2) one or more ion with a partially filled d sub shell

Reply 163

Original post by otrivine

sure!

1) catalysts, coloured compounds, variable oxidation states and are metals which are hard. Have partially filled d sub shells

2) one or more ion with a partially filled d sub shell

Correct!

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Reply 164

Original post by MathsNerd1

Correct!

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Give the half equations and full balanced equation (overall) when titrating between mangangate and when Fe3+ is reduced to Fe2+ (4)

Reply 165

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Original post by otrivine

Give the half equations and full balanced equation (overall) when titrating between mangangate and when Fe3+ is reduced to Fe2+ (4)

It'll be easier posting the picture instead of writing it all out.

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Reply 166

Original post by MathsNerd1

It'll be easier posting the picture instead of writing it all out.

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Perfect!!

my turn

Reply 167

Original post by otrivine

Perfect!!

my turn

Okay, 1 more each then I'm onto the other unit. Here's yours

Question 7 if it wasn't already obvious :smile:

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Reply 168

Original post by MathsNerd1

Okay, 1 more each then I'm onto the other unit. Here's yours

Question 7 if it wasn't already obvious :smile:

that took quite long!

ok

1) 8H⁺+ MNO4^- + 5e^- --> Mn²⁺ + 4h2o

2) 6H⁺ + 5(COOH)₂ + 2MNO4^- ---> 10CO2 +2Mn²⁺ + 8H20

3) concentration = 0.03 mol dm-3

Reply 169

Original post by otrivine

that took quite long!

ok

1) 8H⁺+ MNO4^- + 5e^- --> Mn²⁺ + 4h2o

2) 6H⁺ + 5(COOH)₂ + 2MNO4^- ---> 10CO2 +2Mn²⁺ + 8H20

3) concentration = 0.03 mol dm-3

That's all correct! Last one for me now :smile:

Reply 170

Original post by MathsNerd1

That's all correct! Last one for me now :smile:

ok

For each of the unbalanced redox equations below:

a) MnO4- + U3+ → Mn2+ + UO2+ in aqueous acid (H+ present) conditions
b) Cr2O72- + C2O42- → CO2 + Cr3+ in aqueous acid (H+ present) solutions

(i) Identify which species is the oxidizing agent and which is the reducing agent.

(ii) Write the balanced half-equations for the oxidation half reaction and the reduction half reaction

(iii) Balance the redox equation
(12 marks)

Reply 171

Original post by otrivine

ok

For each of the unbalanced redox equations below:

a)MnO4- + U3+ → Mn2+ + UO2+ in aqueous acid (H+ present) conditions
b)Cr2O72- + C2O42- → CO2 + Cr3+ in aqueous acid (H+ present) solutions

(i) Identify which species is the oxidizing agent and which is the reducing agent.

(ii) Write the balanced half-equations for the oxidation half reaction and the reduction half reaction

(iii) Balance the redox equation
(12 marks)

Oh how kind are you! This might take a while and I'm still eating to I could be some time, just check back again in about 30 minutes :tongue:

Reply 172

Original post by MathsNerd1

Oh how kind are you! This might take a while and I'm still eating to I could be some time, just check back again in about 30 minutes :tongue:

hahahaha , thank you, I am an examiner :colone:

Reply 173

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Original post by otrivine

ok

For each of the unbalanced redox equations below:

a)MnO4- + U3+ → Mn2+ + UO2+ in aqueous acid (H+ present) conditions
b)Cr2O72- + C2O42- → CO2 + Cr3+ in aqueous acid (H+ present) solutions

(i) Identify which species is the oxidizing agent and which is the reducing agent.

(ii) Write the balanced half-equations for the oxidation half reaction and the reduction half reaction

(iii) Balance the redox equation
(12 marks)

Okay I think this is correct for the first one. I'm getting slightly stuck on the half equation part of the second one though :-/

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Reply 174

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Original post by otrivine

hahahaha , thank you, I am an examiner :colone:

What do I do next as I don't see how I can remove the second carbon molecule :-/

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Reply 175

Original post by MathsNerd1

What do I do next as I don't see how I can remove the second carbon molecule :-/

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Okay , tomorrow I will send an attachment with the correct solutions :smile:

yup you are correct by the way regarding the first equationm

Reply 176

Original post by otrivine

Okay , tomorrow I will send an attachment with the correct solutions :smile:

yup you are correct by the way regarding the first equationm

Okay, thanks and I'm glad I at least got the first one correct, I also apologise about my handwriting as I assume you struggled reading it? Most people tend to :tongue:

And I'm now determined to work this thing out! Forget unit 1 now, I'm completing this first.

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Reply 177

Original post by MathsNerd1

Okay, thanks and I'm glad I at least got the first one correct, I also apologise about my handwriting as I assume you struggled reading it? Most people tend to :tongue:

And I'm now determined to work this thing out! Forget unit 1 now, I'm completing this first.

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hahaha no worries!

do it then ill mark :smile:

Reply 178