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Chemistry Help HERE ONLY !!
Naruto:
well i think that colour will be black ,because iodide is reduced to iodine and it is a black solid in colour... +rep if i m correct ;)
Shogun:
hey lana
it goes like this
3 mols of co2 give 15 cm3
so what will 5 mols of oxygen give?
its simply cross multiplication
no. of mols volume
3 15
5 ?
so (5 x 15)
---------= 25cm3
3
then to get the volume for propanol (C3H8) which is 1 mol ,do the same
no. of mols volume
3 15
1 ?
so (1 x 15)
---------- = 5cm3
3
so the answer is for oxygen=25 and for propanol=5
hope u understand, any confusion or difficluties or help, plz do ask me
ap105:
@ gonnagetana:
Hello ! I'm new here .... ermm ... Potassium iodide by itself is white in colour .... Aged and impure samples are yellow because of
oxidation of the iodide to iodine ...
Since the iodide ion is a mild reducing agent, I? is easily oxidised to I2 by powerful oxidising agents such as chlorine:
2 KI(aq) + Cl2(aq) ? 2 KCl + I2(aq)
This reaction is employed in the isolation of iodine from natural sources. Even air will oxidize iodide as evidenced by the observation of a purple extract when aged samples of KI are rinsed with dichloromethane. As formed under acidic conditions, hydroiodic acid (HI) is a stronger reducing agent.[3][4][5]
Like other iodide salts, KI forms I3? when combined with elemental iodine.
KI(aq) + I2(s) ? KI3(aq)
Unlike I2, I3? salts can be highly water-soluble. Through this reaction iodine is used in redox titrations. Aqueous KI3, "Lugol's solution," are used as disinfectants and as etchants for gold surfaces.
Potassium iodide is the precursor to silver(I) iodide, which are used for high speed photographic film:
KI(aq) + AgNO3(aq) ? AgI(s) + KNO3(aq)
Hence, Chlorine is reacted with KI to obtain Iodine
KI + HCl (strong reducing agent - stronger than the iodide ion) --> No reaction -- both reagents are water soluble
Source: Wikipedia & http://answers.yahoo.com/question/index?qid=20070919134841AAUqbvK ... :P
Hope this helps !
Nanavel:
An alloy contains zinc and Copper . A small sample of this alloy was dissolved in acid to give a soluion containing zinc and copper ions.
Explain what would happen when an excess of each of the following reagents is separatly added to this solution.
i) Iron Fillings
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------------------------------------------------------------------------------------------ [2]
ii) Sodium Hydroxide
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MaNa:
i am not sure but
when NaOn is added to a solution contain Cu Deep dark blue solution is foremed
n even with Zn it forms White ppl :S
wite Iron filing i guess the solution turns into blue to grrenish/reddish :S
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