Top Score Gchem

[noshnosh]

Advertisement - Members don't see this ad

Hey guys,I'm was doing top score 1st test and there are at least 3 Q that I thought might been mistakenly answered or I'm an idiot.

They are #45,#53,#53

I appriciate any advice.

 

[noshnosh]

#52,I think the oxidizing agent should be CO and not Pbo.Cause,CO gain an electron and couse Pbo to loos electron (oxygen)?!


For 45, I keep doing it but the answer that I get doesn't exist there.
here what I do:
(16*3)+(23*2)=94
156-94=42/2=21 so Z should be 21g/mol

And #53,I don't get it!!!!!!

 

[orthdent786]

for # 45 --> 156-94= 62/2= 31

btw you can just go to the quesion and it says solution on the bottom right click on that and the solution pops up.

 

[noshnosh]

for # 45 --> 156-94= 62/2= 31

btw you can just go to the quesion and it says solution on the bottom right click on that and the solution pops up.

Didn't I say so that I'm an idiot.These are all result of studying too much then you can not come up with a right answer for a simple calculation.I cannot believe that I was keep getting 42 as a result!!!!!

 

[shawny8351]

find the oxidizing # for all. it's much easier.
PbO + CO = Pb + CO2
Pb=+2 C= +2 0 C=+4

definition of oxidizing agent is that one oxidize other elements by reducing itself.
reduction is gaining electron. if you gain electron, which has negative charge, the oxidizing number decreases. therefore, PbO is being reduced in the above reaction.
from 2+ to 0. the change is -2, by gaining two electron.

so.. final answer is PbO = oxidizing agent.

i may have concept idea wrong.. but i am pretty confident with you way to find an oxidizing agents.

please let me know if i'm wrong