Tuesday
July 29, 2014

Homework Help: Chem- follow up question

Posted by Joe on Sunday, February 28, 2010 at 2:03pm.

Sorry i posted this as an answer after my question had been answered, this is continued from the qualitative analysis question:

That reallly cleared some things up, but I do still have a few questions. Umm im not completely clear on the hyrogen peroxide subject. its added to a solution containing aluminum chloride and iron chloride, and you said it is ther eto make sure the ion is Al3+, can you please explain that bit. Also is it assumed that the chloride ions dissociate in the solution on their own, and can hydrogen peroxide not contribute to making Al ions into Al(OH)3.

Also in the experiment excess NaOH was added like you said, and the precipitate which formed was treated with a little bit of water and H2SO4, before being treated with KSCN. Im wondering whether theprecipitate was treated with H2SO4 simply to dissolve hte precipitate , or whether it had another function also.

Lastly, the liquid portion of teh solution, from the step where hydrogen peroxide and excess NaOH were added, is suposed to contain the Al(OH)3 like you said. This is then made acidic by the addition of HNO3 before being boiled and treated with NH3. i understand it would precipitate when NH3 was added, but im not totaly clear about why the solution was made acidic first as it was already in liquid form.

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

calorimetry - please, someone answer my question i posted already I answered ...
Criminal Justice - Ciminal Justice Question: A police officer takes an official ...
CHEM (DrBob222) - I had posted the question to that previous chem question, ...
arithmetic - I know that this question had already been answered. But still I ...
Bob Pursley - Bob: Thank you for answering my Chemistry question. I apologize ...
physics - Tarzan wights 820N, swings from a cliff at the end of a 20m vine that ...
Chem Question? - I answered this question already, but would like you to check ...
linear analysis - how do i solve for y(x) if dy/dx=x+y and y(0)=1 I know the ...
Science EASY HELP - I had posted this question before but no one answered for ...
algebra - Need some one check my homework. Evaluate 3p/q when p=2 and q=6. ...

Search
Members