[Rabisi]

(Original post by tamil4)
oh dear I put soap down for the second part of the first question

You will probably get the mark as it says what is made using sodium hydroxide. I think i covered myself as i said soap which is a detergent.

[Rabisi]

The answer to the titration one was 9.75, as according to a previous mark scheme concordant in titrations is to within 0.2. So you discount the other reading.

[Rabisi]

(Original post by hypanx)
btw do you know what formulas we need to learn (not the ones provided)? Forgot about them

N multiplied by E all over T. This is to work out the current. N is the number of electrons, E is the electrical charge in coulombs and T is the time in seconds. They pretty much always put that in.

[LostPlanet2Luke]

(Original post by Rabisi)
You will probably get the mark as it says what is made using sodium hydroxide. I think i covered myself as i said soap which is a detergent.

But a soap and a detergent are different substances. They have different behaviours in hard and soft water and have different structures.

[kushrav123]

hey does anyone know what grade boundaries are for the chemistry papers thankssss

[LostPlanet2Luke]

Well i needed 56/60 for overall a*:

I think i lost (1) on the titration HCl average as i put 10 (forgot to discard non-concordant data)
I think i lost (1) on the last question as i divided instead of multiplied (got confused with the unit as grams not dm)
I may have lost (1) or (2) on the acid test without indicator question, i put react with alkali (wrong) but put about limewater and cod2 so hopefully i get (1) there if they are more lenient.
I may have lost (1) by putting copper is malleable so can be shaped and manipulated (forgot ductile FFS).

[GreatArtist2012]

(Original post by Coveted Ul)
Q1) That would be correct, because it said why we shouldn't waste water.
Q2) Correct, compound and salt would be the same, but you'd lose the other mark; you'll need to refer "into the blue flame".
Q3) Incorrect, as the temperature increases the yield decreases, even though the rate of reaction is high.
Q4) I think it would be correct, it did say mention a different one so yes.
Q5) Incorrect, you'll need the 2nd titration as well to find the accurate average for the volume of HCl.
Q6) Correct, it doesn't matter which order, you'll still get the marks.

For the Sodium Carbonate and Potassium Carbonate question, will i have got the three marks for saying

-Use a Flame Test
-Sodium produces a yellow flame
-Potassium produces a Lilac Flame

[LostPlanet2Luke]

(Original post by GreatArtist2012)
For the Sodium Carbonate and Potassium Carbonate question, will i have got the three marks for saying

-Use a Flame Test
-Sodium produces a yellow flame
-Potassium produces a Lilac Flame

Its difficult to say but my guess would be you would only get 1 amrk for that if the methodology for HOW to carry out the flame test was very briefly explained. My prediction is that the individual marks were for:

1) Preparation of flame test- cleaning of wire loop etc.
2) How to carry it out- Dip in metal then IN the flame of the bunsen burner.
3) Identification of ions: sodium-Yellow flame Potassium-Lilac.

THIS IS MY GUESS, I INCLUDED BOTH TO COVER MYSELF BUT HOPEFULLY U GET THE MARKS.

[Krakykelly]

Hey guys, I think it went really well Does anyone have a copy of the exam paper?
I only needed 42 for an A* so I definitely think I got it

[escarr15]

(Original post by lettucesoap)
Did anyone else get 212 for one of the questions and think of that Azaelia Banks song?

I put detergents for for the second part of question one, as soaps was the answer for the first one I didn't think they'd put the same answer twice.

Also, for the definition of 'pigments' question, I put an insoluble compound used in paints. Do you guys think I would've got the mark?

I really really need to hit the A*. I hope you all get what you were aiming for!

YES! Except I thought of the Beccy Huxtable off of Scott Mills version of 212 :P
i guessed the pigments one so you're probably more right than me

[OllieGCSEs]

Does anyone want to hazard a guess at the grade boundaries? We all seemed to find it easy so i expect they're going to be much higher this year

[Coveted Ul]

probably it will be 56/60 for an A*

The average answer is 9.677 if you got any other number it would be wrong

[nervouspupil123]

(Original post by Coveted Ul)
probably it will be 56/60 for an A*

The average answer is 9.677 if you got any other number it would be wrong

You seem pretty sure...but I'm pretty sure it was what i said

[Nick0110]

(Original post by Coveted Ul)
probably it will be 56/60 for an A*

The average answer is 9.677 if you got any other number it would be wrong

No Sir, you are in fact wrong. When doing titrations - chemists like to be very very thorough. The numbers given were 9.8 , 9,7, 10.0 and 10.4. To be thorough enough you must wain until you have two numbers which are within .1 of each other and use them (the whole point of repeating titrations). So the answer was to take 9.7 and 9.8 and average them: 9.75. Sorry for bursting anyone's bubble- this was in a couple of past papers but is also common knowledge.

[sophiekutie]

(Original post by nervouspupil123)
****! i put that, and then i remembered there was only 99% conversion so i put 990 gutted cos if id got that i defo would have got an A*

also, is the overall boundary for an A* always 360? or is it ever slightly higher/lower because i needed 57/60 to get 360, and i think i got 56-58 :/

it's always 360... hence why the cource is called Edexcel 360 science!

[sophiekutie]

(Original post by Nick0110)
No Sir, you are in fact wrong. When doing titrations - chemists like to be very very thorough. The numbers given were 9.8 , 9,7, 10.0 and 10.4. To be thorough enough you must wain until you have two numbers which are within .1 of each other and use them (the whole point of repeating titrations). So the answer was to take 9.7 and 9.8 and average them: 9.75. Sorry for bursting anyone's bubble- this was in a couple of past papers but is also common knowledge.

yes i agree with this comment, you must wait until there are correlating results to allow for removing anomalies/tests

[LostPlanet2Luke]

(Original post by Nick0110)
No Sir, you are in fact wrong. When doing titrations - chemists like to be very very thorough. The numbers given were 9.8 , 9,7, 10.0 and 10.4. To be thorough enough you must wain until you have two numbers which are within .1 of each other and use them (the whole point of repeating titrations). So the answer was to take 9.7 and 9.8 and average them: 9.75. Sorry for bursting anyone's bubble- this was in a couple of past papers but is also common knowledge.

Very correct although it is considered concordant if the readings are 0.2 apart not just 0.1 apart! I put 10 as i did it completely wrong, im truly gutted that i got it wrong considering i needed 56/60 for an a* and every mark counted really

[sophiekutie]

(Original post by nervouspupil123)
2 IAA, 3 Multiple Choice, 1 practical skills and 1 of the written (short written) are worth 40 ums each = 280 (prior to the final written exam)
The final written exam is worth 120 ums- bringing the total to 400ums.

You need 360 for an A*, 320 for an A, 280 for a B, 240 for a C etc.
So if you've got the multiple choice and the final paper still to do, you will have a score out of 240 right now. 90% of 240 (216) is an A*, 80% A etc. So work out what you're on, say, 220. This would mean out of the possible 160 ums remaining you would need 100 more for an A, or 140 more for an A*; from there you can work out targets for the individual exams; hope this helps.

Erm my school gave us our ums's so far out of 120 and said that that was however many marks we needed to get on this exam which makes no sense...

i've only had A*'s before in chemistry but they said i needed 99 ums on this exam to get an A* overall?

help?

[LostPlanet2Luke]

Would "malleable" be acceptable for the copper wiring question as I put so it can be manipulated into shapes of wires?

[Coveted Ul]

No, only if you had said it for the copper saucepans.