July 03, 2020, 11:53:27 AM
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Topic: why aluminium chloride solution is pale yellow.  (Read 557 times)

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Offline Aniket

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why aluminium chloride solution is pale yellow.
« on: June 12, 2020, 12:37:14 AM »
Dear Feiends,

Al2(So4)3 + 3Na2Co3+3H2O -------> 2Al(OH)3+3co2+3Na2So4
342.15      +317.94    +54     --------> 156+132.03+426.12

As per this Equation formation of aluminium hydroxide is 156 gm theoritically but practically got higher yield why?

is there any other formation during reaction ?

Offline AWK

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Re: mole balance not justify in this reaction why?
« Reply #1 on: June 12, 2020, 01:18:01 AM »
From inaccurate work, you should not immediately draw subversive conclusions for chemistry.
For aluminum hydroxide, thorough washing of the precipitate and subsequent long drying is very important.
Capital letters for elements are also very important
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Online chenbeier

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Re: mole balance not justify in this reaction why?
« Reply #2 on: June 12, 2020, 01:18:28 AM »
How do you check your Product. Weight? Dry enough, maybe also sodiumtetrahydroxyaluminate Na[Al(OH)4]?

Offline AWK

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Re: mole balance not justify in this reaction why?
« Reply #3 on: June 12, 2020, 01:24:02 AM »
Sodium tetrahydroxyaluminate Na[Al(OH)4] is rather not important for this reaction with sodium carbonate. Moreover, this compound is soluble in water.
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Offline Aniket

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Re: mole balance not justify in this reaction why?
« Reply #4 on: June 12, 2020, 05:16:30 AM »
Dear Sir,

Drying method is spray drying.

Product pass in British Pharmacopoeial Requirements.No chance of any impurity or other salt.

Offline Borek

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Re: mole balance not justify in this reaction why?
« Reply #5 on: June 12, 2020, 06:18:28 AM »
Getting a stoichiometric amount of amorphous solid that is difficult to wash/filter out/dry would be a miracle.

If there is more than expected it is either contaminated by some byproduct of the reaction or still wet.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info, pH-meter.info

Offline Aniket

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Re: mole balance not justify in this reaction why?
« Reply #6 on: June 12, 2020, 07:24:46 AM »
Dear Sir,

One more confusion why aluminium hydroxide react with HCL to give yellow colour solution.

its due to amorphous nature of aluminium carbonate or bicarbonate?

Offline AWK

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Re: mole balance not justify in this reaction why?
« Reply #7 on: June 12, 2020, 07:57:20 AM »
Something went wrong, but this does not give rise to questioning the stoichiometry of the reaction. This has to be analyzed on-site.
As for the yellow color after adding HCl to Al(OH)3 - some reagents must be contaminated. Iron chloride (both II and III) in excess of HCl is practically colorless.
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Re: mole balance not justify in this reaction why?
« Reply #8 on: June 12, 2020, 10:54:12 AM »
Dear Sir,

Drying method is spray drying.

Product pass in British Pharmacopoeial Requirements.No chance of any impurity or other salt.

Additionally did ypu check the equipment?  If the preperation done in glasfree vessels maybe some metal part is attacked by the acid.

Offline Aniket

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Re: mole balance not justify in this reaction why?
« Reply #9 on: June 13, 2020, 12:48:26 AM »
Dear Sir,

we final concluded that during reaction amorphous solid formation occur that why increase yield.

but cant understand for yellow colour liquid produce during reaction of aluminium hydroxide with HCL.

aluminium hydroxide contain less than 100 ppm iron and HCL AR grade contain less than 10 ppm iron.

sir yellow colour is only due to iron impurity?


Offline AWK

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Re: mole balance not justify in this reaction why?
« Reply #10 on: June 13, 2020, 02:39:38 AM »
Different polymorphs of the same compound may have different colors, but when dissolved in hydrochloric acid - their solutions will show the same color.
Iron with a concentration above 1 ppm can be determined colorimetrically, qualitatively even visually, roughly quantitatively - by comparison with the color scale.
Higher mass after drying results rather from shorter time or lower drying temperature (amorphous aluminum hydroxide may need more time for drying).
100 ppm Fe3+ in HCl is rather colorless - it can be easily checked in the lab.
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Offline Aniket

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why aluminium chloride solution is pale yellow.
« Reply #11 on: June 17, 2020, 08:11:46 AM »
Dear Friends,

we cant understand aluminium chloride is transparent liquid as per theoretically. but in market we seen pale yellow solution.

we also understand about iron chloride impurity may cause yellow solution but iron is only 25 ppm.

so ,please give suggestion why this will happen?

Offline billnotgatez

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Re: why aluminium chloride solution is pale yellow.
« Reply #12 on: June 17, 2020, 11:42:33 AM »
@Aniket
I have merged your old thread with this newer thread because of the similarity.

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