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Cambridge Chemistry Challenge

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Reply 2700

Axdhdmrffjcj

Original post by DororoW

For copper do you get symbols as Na,K,Fe,Ag,Sn,Au,Hg,Pb

Yeh but you want the missing ones from the trend - compare the element names with their symbols

Reply 2701

robb2304

guys can i have help with silver i get maybe theres a in written code in the numbers down the page but im confused and my head hurts

Reply 2702

alow

Original post by robb2304

guys can i have help with silver i get maybe theres a in written code in the numbers down the page but im confused and my head hurts

Look at the formula for the compound that the fire extinguisher in the picture contains. Notice anything?

Reply 2703

fizzers

Original post by robb2304

guys can i have help with silver i get maybe theres a in written code in the numbers down the page but im confused and my head hurts

No don't over-think this!! It's about halons- molecules consisting of carbon, maybe hydrogen and at least one halogen. The numbers on the left are the halon numbers and the right their molar masses. Good luck!!!

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any hints for gold?

Did it! Eugh I forgot STP is different to RTP which cost me about 20 minutes :lol:

Reply 2706

robb2304

okay guys i cant understand why this is wrong so i will go through my reasoning
i think the way the numbers work is the first number is the number of carbons the second is f 3 cl 4 br 5 i so e.g 1211 CF2Cl1Br1= 165.4 mr
i did this for the others and it worked unless ive made mistakes without noticing
so for 54321 i got as C5F4Cl3Br2I then H2 so its saturated thus this gives me
5*12+4*19+3*35.5+2*79.9+1*126.9+2*1=531.2 but this is wrong would apreciate help