Didn't the vanadium E cell one say that the sign of the vanadium half cell was the same sign as the one in the question which was iron? So it must've been +1.80V, since the iron half cell was positive?

Reply 444

lyricalvibe

16

Original post by Kira Yagami

I out 0.26 for the e cell, that wrong?

I got that too

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Reply 445

charmantell

1

For the use of the membrane question in the cell, I put that it balances out the charges between the two half-cells. Would this be worth a mark?

For the partial hydrolysis question I just put the two forms of the amino acid - one with an NH3+ group and another with a COO- group. I understand this is likely to be wrong.

I got +0.26 for the E cell - I am confused why people are getting -0.26?

EDIT: I now understand how it was -0.26... what a silly mark to lose.

(edited 7 years ago)

Reply 446

geor_thor

7

I got 0.26V for the E cell value

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Reply 447

Zuzuvela

2

Can we put F334 behind us now. Just sum it up like this. Cold drawing came up for the first time. 3 marks. Its one sentence in the OCR endorsed revision guide.
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Reply 448

LewisEdwards1234

1

Original post by charmantell

For the use of the membrane question in the cell, I put that it balances out the charges between the two half-cells. Would this be worth a mark?

For the partial hydrolysis question I just put the two forms of the amino acid - one with an NH3+ group and another with a COO- group. I understand this is likely to be wrong.

I got +0.26 for the E cell - I am confused why people are getting -0.26?

In terms of the Ecell if it was +0.77-0.26v it would not make 1.03 which was stated in the question. Instead i did 1.8v which 1.8-0.77 is 1.03v but this could be completely wrong on my part.

Reply 449

username1084917

16

For cold drawing i didn't say about the neck but i said everything else would i lose any marks?

And for the IMF's i said H-B and I-D in amide and P-D and I-D in ester and then talked about the standard stuff?

Reply 450

geor_thor

7

But as 0.26 v is the negative half cell you have to do 0.77- - 0.26 because the less positive half cell is always taken away from the more positive one.Two minuses make a plus so that means that 0.77 + 0.26 = 1.03 v. I may be completely wrong though.

Reply 451

geor_thor

7

Original post by Kira Yagami

For cold drawing i didn't say about the neck but i said everything else would i lose any marks?

And for the IMF's i said H-B and I-D in amide and P-D and I-D in ester and then talked about the standard stuff?

I don't think you would lose marks.

Reply 452

Marli-Ruth

2

E cell was -0.26 V

Need to have the minus sign to get the mark.

Reply 453

Marli-Ruth

2

Cold drawing was 3 marks
I said about necking...increases crystallinity...chains more linear....

Forgot to talk about chains being closer together.. Maybe 2/3 for me then?? Anyone??