Question #6c52e

1 Answer
Apr 11, 2015

The easiest way to go about solving solubility problems is to examine the solubility rules

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So, starting with mercury (I) chloride, or Hg2Cl2. As you can see, you're dealing with a halide or, more specifically, with a chloride. Notice that all halides are soluble with the exception of those formed with three cations, including Hg2+.

As a result, mercury (I) chloride will be insoluble in water.

Use the same approach for all the compounds listed.

Sodium sulfide, or Na2S, is soluble in water because all compounds that contain the sodium cation, Na+, are soluble in water. The same is true for compounds that contain the ammonium ion, NH+4, so ammonium phosphate, (NH4)3PO4 is soluble in water.

Cadmium carbonate, CdCO3, and lead (II) sulfate, PbSO4, are both insoluble in water because they do no represent soluble exceptions for compounds formed with the carbonate, CO23, and phosphate, PO34 anions.