what did u guys put ? cryolite and ______ i put bauxite
what did u put for the improvement of the experiment?
what did u say for the dental braces? i said nitinol makes it stronger and is a memory alloy and can maintain its shape
what did up put for the difference in structure in an alloy and a metal - i said an alloy contains atoms of different metals so the layers are rough and cannot slide over eachother meaning that an alloy is stronger
what did u say for why a coin isn't pure copper - i said it would lose shape.

for the cryolite I put bauxite but it is aluminium oxide according to the revision guide

Reply 465

Bubblebex1

Original post by ruqayyah12334

I put aluminium oxide :frown:

So did I because before electrolysis aluminium oxide is separated from its ore "bauxite" so in electrolysis the solution is aluminium oxide

Reply 466

RR151215

Original post by ellen199

for c3 was the volume of hydrochloric acid 60? it said total so wasn't to sure .. think it may of been 30 but was trying to confuse us haha

I think it was 55. 25 initially then add 30 as it was added in 5cm^3 intervals.

Reply 467

BenAtkinson

haha that was piss easy lads

Reply 468

mimibrockstark

Also, I put 'smart alloy' instead of 'memory alloy', on the question about the braces. Will I still gain a mark?

Reply 469

Pidge Gunderson

Original post by mimibrockstark

Also, I put 'smart alloy' instead of 'memory alloy', on the question about the braces. Will I still gain a mark?

I didn't put either I just said what it does

Reply 470

tombirchy

I revised, but the paper was bitty. I self marked at the end at I think I got 49/60

Reply 471

belmedic

Original post by mimibrockstark

I thought the empirical formula was diving the relative atomic number with the amount needed? How is it Pb2O3?

Pb= 6.21g and O=0.72g
Pb's Ar= 207 and O's= 16
6.21/207=0.03 Moles
.72/16=0.045 Moles

0.03/0.03=1
0.045/0.03=1.5
So the ratio is 1:1.5
to get whole numbers, multiply both sides by 2 to get 2:3
so the formula is Pb2O3

Reply 472

mimibrockstark

Can someone tell me how they solved the empirical formula because I am confused on how my answer was different. C2.

Reply 473

mimibrockstark

Original post by isabelsummers

Thankyou so much! I got the first section correct, hopefully there was a few marks gained there :/

Reply 474

Amy Hickman

For improvements to the experiment i put stir it ?? Is that acceptable or?

Reply 475

emileepifanoff

What did you guys put for the C2 6 marker?

I put that the reason that experiment 7-10's temperature stayed the same was because the glass beaker wasn't insulated therefore the rate at which heat energy
was being lost was equal to the heat energy being produced.

Reply 476

thomasallen

To be honest I'm so happy that it looks like I got the empirical formula one right, as well as a few of the other difficult ones in C2. Really wasn't expecting to do as well as it looks like I did, since everyone at my school was so negative about C2 like it was some impossible paper or something.

Reply 477

belmedic

Original post by mimibrockstark

Can someone tell me how they solved the empirical formula because I am confused on how my answer was different. C2.

Reply 478

Palette

What did everyone put for the soft water 6 marker?

I put CaCO3 in Method 2 must be removed....

but I made nonsense for the advantages, for example, I wrote limestone/CaCO3 can be collected (when this method is done on an industrial scale) and used for buildings preserving existing reserves of limestone.