Solving Solubility of Unknown Compound in Base

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The discussion focuses on identifying an unknown compound through solubility tests in 5% NaOH and subsequent neutralization with 5% HCl. The solubility test indicated that the unknown compound, referred to as HA, is an organic acid, as evidenced by the formation of turbidity upon adding HCl to the supernatant containing the conjugate base A-. The reaction equations HA (unknown) + OH- <-> H2O + A- and A- + HCl <-> Cl- + HA confirm the behavior of the compound during the tests. The turbidity observed is attributed to the precipitation of the organic acid HA when H+ ions are introduced.

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In my lab, I'm trying to identify an unknown compound. So I did a solubility test of the unknown into 5% NaOH. According to the manual it said that if it appears insoluble,take the supernatant out and add 5% HCl until neutral. If percipitate or turbidity results, it means the unknown is an acid.
So far I thought this:
HA (unknown) + OH- <-> H20 + A-
I'm assuming the conjugate base was in the supernatant, but I'm not sure.
A- + HCl <-> Cl- + HA
I'm not sure where the percipitate or turbidity is from. Please help me!
 
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In the first part, the organic acid present dissolved (why you obtained the very soluble A anion). Later, you added H+ which recombined with the A- giving you back the fairly insoluble organic acid again, the HA. The HA causes this turbidity or precipitation.
 

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