Using reagents to identify unknown substances

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The discussion focuses on using reagents like KOH and H2SO4 to identify unknown substances in a lab setting. Participants highlight that certain reagents, such as AgNO3, will precipitate when mixed with solutions containing halide ions, forming a solid like AgBr. Acids like HCl and H2SO4 can indicate the presence of carbonates or sulfites through gas evolution, evidenced by fizzing. KOH can also produce precipitates depending on the ionic compounds present, with hydroxides generally being insoluble. Understanding these reactions and consulting a solubility chart can aid in identifying the unknown substances effectively.
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My group has to design a lab based on the materials and purpose our teacher gave us. The purpose is to identify some unknown substances. One of the tests that we will conduct is the KOH (aq) and H2SO4 (aq) reagents tests. The teacher gave us the following example:

suppose
NaBr (s) --> Na+ (aq) + Br- (aq)
AgNO3 (s) --> Ag+ (aq) + NO6- (aq)

If the solutions are mixed,
Na+ (aq) + Br- (aq) + Ar+ (aq) + NO3- (aq) --> AgBr (s)

AgBr (s) is the precipitate, so what is in the mixture will be:

AgBr (s) + Na+ (aq) + NO3-(aq)


I have no idea how to apply that example to identify substances, and am still a bit unclear on how reagents work. Can someone give me a hand?

Thanks in advance!
 
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certain reagents like AgNO3, when added to a sample that has a halide ion in it like cl-, Br- or I-, it will always give a ppt (solid)

acids like HCl or H2SO4 can tell you if carbonate or sulfites are present because they will give off a gas (fizzing) - what is the reaction?

KOH can also give ppt, depending on what is in solution. there should be a solubility chart of ionic compounds somewhere in your textbook. the things that make ppt or gases will have similar ions

ex hydroxides are mostly insoluble so a rxn of Fe3+ and KOH will give a red ppt (of what?)