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    A dye can be made from 4-methylphenylamine and 2,6-dimethylphenol, shown below(well they are in my paper, I can't get a picture on here though )

    4-methylphenylamine is dissolved in ice-cold hydrochloric acid and sodium nitrite is added. This mixture is then slowly added to an alkaline solution of the phenol to form the dye.

    1i) Identify the nitrogen containing compound formed by the mixture of hydrochloric acid and sodium nitrite(I thought initially it would be NaCl, but it says nitrogen-containing, so I'm stuck)

    (ii)Draw the structure of the organic compound formed in the ice cold acidic mixture, showing a displayed formula of the nitrogen-containing group.

    So my thoughts, would the oxygens on the nitrite substitute off the hydrogens on the amine group?

    (iii) state the name of the type of organic compound drawn in (ii) I can't do because I haven't drawn anything

    (iv) suggest why the mixture must be kept at a low temperature(is this because you could form something explosive like tnt?)

    (v) suggest the structure of the dye

    Sorry, there are quite a few parts to this question, but I don't know any of them, please help
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    (Original post by Eloades11)
    A dye can be made from 4-methylphenylamine and 2,6-dimethylphenol, shown below(well they are in my paper, I can't get a picture on here though )

    4-methylphenylamine is dissolved in ice-cold hydrochloric acid and sodium nitrite is added. This mixture is then slowly added to an alkaline solution of the phenol to form the dye.

    1i) Identify the nitrogen containing compound formed by the mixture of hydrochloric acid and sodium nitrite(I thought initially it would be NaCl, but it says nitrogen-containing, so I'm stuck)

    (ii)Draw the structure of the organic compound formed in the ice cold acidic mixture, showing a displayed formula of the nitrogen-containing group.

    So my thoughts, would the oxygens on the nitrite substitute off the hydrogens on the amine group?

    (iii) state the name of the type of organic compound drawn in (ii) I can't do because I haven't drawn anything

    (iv) suggest why the mixture must be kept at a low temperature(is this because you could form something explosive like tnt?)

    (v) suggest the structure of the dye

    Sorry, there are quite a few parts to this question, but I don't know any of them, please help
    i) would be Nitric Acid I think....
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    (Original post by nicatre)
    i) would be Nitric Acid I think....
    Thanks, I'll go with that for the time being any idea's about the other parts?
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    (Original post by Eloades11)
    Thanks, I'll go with that for the time being any idea's about the other parts?
    I really don't know...I think it's not worded greatly...from "ice cold solution" I'd have thought the organic compound was the nitric acid...or is it referring to something relating to the phenol titration? If so it's an alcohol and an acid, if it was a carboxylic acid it would give an ester but I don't think that's true if it's just a normal acid.

    The only other thing I could think of would be that there is a substitution of the nitrate for either hydrogen of hydroxide kicking of either Hydrogen gas or water...
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    HNO2 is nitrous acid, not nitric
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    iv) otherwise the diazonium salt will decompose?
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    (Original post by Jhyzone)
    iv) otherwise the diazonium salt will decompose?
    and explode in the process
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    (Original post by Eloades11)
    A dye can be made from 4-methylphenylamine and 2,6-dimethylphenol, shown below(well they are in my paper, I can't get a picture on here though )

    4-methylphenylamine is dissolved in ice-cold hydrochloric acid and sodium nitrite is added. This mixture is then slowly added to an alkaline solution of the phenol to form the dye.

    1i) Identify the nitrogen containing compound formed by the mixture of hydrochloric acid and sodium nitrite(I thought initially it would be NaCl, but it says nitrogen-containing, so I'm stuck)

    (ii)Draw the structure of the organic compound formed in the ice cold acidic mixture, showing a displayed formula of the nitrogen-containing group.

    So my thoughts, would the oxygens on the nitrite substitute off the hydrogens on the amine group?

    (iii) state the name of the type of organic compound drawn in (ii) I can't do because I haven't drawn anything

    (iv) suggest why the mixture must be kept at a low temperature(is this because you could form something explosive like tnt?)

    (v) suggest the structure of the dye

    Sorry, there are quite a few parts to this question, but I don't know any of them, please help
    You are going to struggle with this as it's a pretty standard preparation of a azo dye, but unless you read up about it you'll never work out what is happening.

    Look up diazotisation and/or reactions of aromatic amines.

    The reaction is not difficult to understand but as hinted by others goes via intermediates adn the reagent itself is unstable to heat.
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    (Original post by charco)
    You are going to struggle with this as it's a pretty standard preparation of a azo dye, but unless you read up about it you'll never work out what is happening.

    Look up diazotisation and/or reactions of aromatic amines.

    The reaction is not difficult to understand but as hinted by others goes via intermediates adn the reagent itself is unstable to heat.
    Oh right, I haven't learnt this yet, our teacher set us the past paper questions and hasn't finished teaching the stuff to us yet. Thanks for your help
 
 
 
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