I have a question that I just can't seem to get my head around, although it's probably obvious and I'm being stupid due to sleep deprivation. So redox reactions! I have two half equations: 1. Fe2+ - e- = Fe3+ 2. 2ClO3 + 12H- = 2Cl- + 6H2O And I need to combine them to make one equation, balancing atoms and charges. Can anyone help me make heads or tails of this?:bang:
chemistry nerd incoming! remember OIL RIG. Oxidation is Lost, Reduction is gain. the first equation is already lost of one electron to Fe 3+, dont need to change anything, yet in the second one, you first need to find the oxidation number of Cl. Chlorate is a neutral charge molecule, and oxygen typically have an oxidation of -2. so 3* -2 = -6, and -6 +x = 0, therefore, the chlorine is +6 the chlorine in the product side is -1 here's how to do redox: 1) assign oxidation number 2) balance atoms for each equation 3) balance charges for each equation without adding atoms. (so if you have one side +4 and another side -3, you would add 7 electrons on the +4 side since you already balanced out the atoms for the half equations) 4) put the two equations together by multiply a coefficient, so that the electron gain is equal to electron lost so if your Reduction side is +6 electron and oxidation is -3 electron, you multiply the oxidation by 2 I actually didn't work the whole thing, so try to do it on your own (!)
I graduated with a B.S. in chemical engineering ^.^ though i havent done redox in forever -.- ... ill get back to you (goes over notes) ...
ok solution Spoiler Fe2+ - e- = Fe3+ you need to move the electron to the other side, never have subtraction Fe2+ = Fe3+ + e- Fe2+(2+) = Fe3+(3+) + e- also oxidation numbers in () 2ClO2 + 12H- = 2Cl- + 6H2O 2Cl(+4)O2(-2*2) + 12H-(-1) = 2Cl-(-1) + 6H2(+1*2)O(-2) oxidation numbers in () first reduce coefficients to lowest factor ClO2 + 6H- = Cl- + 3H2O one thing first H- = 2e- + H+ ClO2 + 12e- + 6H+ = Cl- + 3H2O balance equation for all non-oxygen and hydrogen (Cl is already balanced) then add H2O to balance oxygen in the equation H2O + ClO2 + 12e- + 6H+ = Cl- + 3H2O cancel out H2O on both sides ClO2 + 12e- + 6H+ = CL- + 2H2O now add H+ to balance hydrogen in the equation ClO2 + 12e- + 6H+ = Cl- + 2H2O + 2H+ cancel out H+ on both sides ClO2 + 12e- + 4H+ = Cl- + 2H2O now add e- to balance the charge of the equation ClO2 + 12e- + 4H+ = Cl- + 2H2O + 7e- cancel out e- on both sides ClO2 + 5e- + 4H+ = Cl- + 2H2O now you can almost add the two equations together Fe2+ = Fe3+ + e- ClO2 + 5e- + 4H+ = Cl- + 2H2O multiply each equation by a number so the electrons will cancel out when you add them together 5*(Fe2+ = Fe3+ + e-) = 5Fe2+ = 5Fe3+ + 5e- 1*(ClO2 + 5e- + 4H+ = Cl- + 2H2O) = ClO2 + 5e- + 4H+ = Cl- + 2H2O and add 5Fe2+ ClO2 + 4H+= 5Fe3+ + Cl- + 2H2O ^w^ ----------------------------------------------------------------------------------- also this site has the basic steps to follow HTML: http://chem1180.blogspot.com/2010/11/191-balancing-oxidation-reduction.html
Call me bad, but nowadays I never would like to help someone on the whole way through homework unless they really don't get it I like to give people sense of achievement and pride for understanding a concept, just by giving them some tips and head start. EDIT: I also don't assign oxidation number to everything. HEY, CAN YOU HELP ME WITH ORGANIC CHEMISTRY 1 MECHANISMS? <3 LOL, poke my wall if you need help
To proud to ask for help! I also get into arguments over simple things apparently like today on how in certain reactions you don't have to list water in the reactants which I didn't believe until i heart this really long thing about some kind of boringly named chemistry.
I always use leo the lion says ger because it's funny. It's lose electrons oxidation, gain electrons reduction.
Well, to be fair, high school chemistry is watered down chemistry. Like in college, it's the same class but they give you more insight into why do we do things certain ways. like in my mechanism thing, water as a solvent actually help contribute to the reactions... EDIT: and sh! pick one, pride or grade!
I am in AP chemistry...so it is college lol *slaps my own hand* Me 1 You 0 ( now if that is even something to win in who knows)
I took AP chemistry. Me 1 You 1 OK, no really. I got a 3 and the uni wants a 4. But then when I took it, my professors really make it more interesting. Ok, except I doze off on chemistry 1... evening classes make me sleepy
I wish I took chemistry in college, but no I dropped out of education, now I forgot everything.. I wanted to learn Alchemy, but now I'll have to start from scratch which I can't be asked! So I can't do experiments and make godzilla like shit :tears:
I thought alchemy is out.... of date. You're not talking like, full metal alchemist or like, ancient alchemy?
yeah, I kind of just was OCD mode and then was ... maybe i should spoil it so they can try to solve it first and compare answers yeah, i dont like giving people answers either, hard to teach someone over a forum ... thats also why i linked a class lecture so they can use that well i was just showing oxidation numbers to help teach about them, not very indepth but yeah and i can try to help you with orgo 1 i need to get my notes out took so much orgo in college orgo 1,2,3, synthesis, lab, advanced quantum chemistry for fun, only had to take 1 and 2 for my major ... <3 chemistry ^w^ ---------- Post added 23rd Oct 2012 at 09:51 PM ---------- ha, got 5 and then took test in college to bypass all basic chem classes ^w^ yeah i know I'm a chem snob -.-
OMG. what a nerd! *clear throat* sometimes OCD is bad! How does OP learn this if OP didnt take the time to think this through? lol. I have orgo test on friday and I have yet to figure out how you can help me OVER the internet.... I'll be doing my own practice and problems and things. AND DAMN. All those classes... and I jelly your 5.
if you have questions you can always MS me on my wall and i can try to explain it without being able to write out answers easily ... oh, i knew cis and trans from chemistry, so i understood cis and trans gendered from the start and also kind of use it to explain myself to people i come out to, since more people know chemistry ^.^
good luck trying to draw the flow of electrons and stereochemistry with wedge and dash on the EC wall HAHAHAAH
Some sections of Organic chemistry make me sweat bullets sometimes. At least I know where to come for some advice lol.
