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Thread: a few questions pls :p....

  1. #1 a few questions pls :p.... 
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    i really love chemistry but unfortunate for me i dont have the best teacher.... any questions i ask she tells me to go do research on the net & in the library. & the thing is there is too much info sumtimes.....i just wanted to ask a few questions pls


    is this reaction a Redox reaction or a Substitut reaction
    Copper Sulphate (aq) + Water (aq) + Zinc (s) ---> Zinc Sulphate (aq) + Copper (s) + Hydrogen (g)

    are these properly balanced because my teacher told me there is a special way to balance redox reaction but wont teach me

    Cu (s) + 4HNO3 (aq) ----> Cu(NO3)2 (aq) + 2NO2 (g) + 2H2O (l)
    Copper (s) + Nitric Acid (aq) ----> Copper Nitrate (aq) + Nitrogen Dioxide (g) + water (l)


    Cu2SO4 + 4H2O (l) + Zn (s) ---> ZnSO4 (aq) + Cu (s) + 4H2 (g)
    Copper Sulphate (aq) + Water (aq) + Zinc (s) ---> Zinc Sulphate (aq) + Copper (s) + Hydrogen (g)


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  3. #2  
    Forum Masters Degree organic god's Avatar
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    Yes the first reaction is a redox reaction but i don't think water and hydrogen need to be included

    Coppper Sulphate + Zinc -----> Zinc Sulphate + Copper
    the aqeuous conditions of the copper sulphate kind of indicates water is present.

    This is redox because
    Cu<sup>2+</sup> (aq) ----> Cu(s) (reduction)

    Zn(s) ------> Zn<sup>2+</sup> (oxidation)

    Ok now for the balancing part of your equations.

    The first reaction is wrong because it is not a redox reaction
    General Rule
    Metal + acid ----> Salt + Hydrogen
    Also in the reaction the Nitrate ion is mearly a spectator ion and therefore doesn't have to be included in the reaction

    Cu(s) + 2H<sup>+</sup> (aq) -----------> Cu<sup>2+</sup>(aq) + H<sub>2</sub>

    In the second reaction. This is redox and i have written the equation above in terms of name species so the overall reaction (nitrate spectator ion again)

    Cu<sup>2+</sup>(aq) + Zn(s) ---------> Cu(s) + Zn<sup>2+</sup> (aq)

    p.s. glad to have another chemistry lover on the forum any questions post here and i will be happy to help


    everything is mathematical.
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    Forum Sophomore oceanwave's Avatar
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    yep. OG is right...an additional remark on q1: it's also known as a displacement reaction. in that a more reactive metal displaces the less reactive metal in a solution of ions. u'll prob see reddish copper residue at the bottom of the test tube/beaker.
    What do you do when the last day of your life is approaching...........?
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  5. #4  
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    :? are you sure???? because i asked my teacher & she said that the first one was a redox reaction & i even found a video saying it is a redox process

    isnt it a redox reaction when a metal dissolves into a liquid, and in this case its copper breaking down into Cu+2 .....

    what we did for the first equation was add copper to nitric acid & my teacher said i had to include those things into the equation aswell ..........this is so frustrating....i've spent like 30 hours doing this assigntment & this is all due day after tomo ...............



    sry for my noobishness....
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  6. #5  
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    don't be sorry for asking questions even if you become a great chemist you will still be asking questions..that's were research comes in.

    I think what ocean wave meant is that the reaction is both displacement and redox, however i think if you're teacher called it redox then go with that.

    I also need to correct a previous statement of mine.
    Cu + HNO<sub>3</sub>
    Under normal circumstances copper doesn't react with dilute acids however in this case the reaction isn't a simple metal + acid reaction it is actually a redox reaction.

    Nitric acid is a strong oxidising agent
    This does indeed liberate nitrogen dioxide so your equation is correct.

    snt it a redox reaction when a metal dissolves into a liquid, and in this case its copper breaking down into Cu+2 .....
    Redox is oxidation and reduction taking place at the same time
    everything is mathematical.
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  7. #6  
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    thanks guys you helped me quite a bit..... even if i think i had a heart attack a while ago .....

    ok another quick question just for my own knowledge.
    this is the experiment we did

    Code:
    http://web.lemoyne.edu/~giunta/chm151L/copper.html#reactions
    is there any reason that we should use copper and not another element?
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  8. #7  
    Forum Masters Degree organic god's Avatar
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    If you are interested in this side of chemistry do some research into
    Ligands and look at the metal-aqua ion complexes.
    Also you could look at standard electrode potentials which show you why certain redox reactions occur when others won't
    everything is mathematical.
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  9. #8  
    Forum Sophomore oceanwave's Avatar
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    yep. i was referring to the fact that they could also be called displacement reactions (tho they are a rather crude term actually). but yea. sry if i caused the minor heart attack
    What do you do when the last day of your life is approaching...........?
    Me?
    I still go about living life the way I always have.
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  10. #9  
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    WOOOT!!!!!! i got an A!!!!


    COOKIES FOR EVRYONEEEEE!!!!!!



    i wanna know if anybody wants to ook at my asignment and give me a lil critique....cause i no likey my science teacher.....
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  11. #10  
    Forum Masters Degree organic god's Avatar
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    i'll gladly take a look at it for you emu, i always like to look at scientific reports (it's like art to me) and i do have some experience in them
    everything is mathematical.
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