Answer:
a. Na₂S and (NH₄)₃PO₄
.
Explanation:
To know which salts are soluble we need to remember some <em>solubility rules</em>. And apply these as follows:
* All compounds of group 1 (Li⁺, Na⁺, K⁺, etc.) are soluble, Na₂S is soluble.
* All ammonium salts are soluble,
<h3>
(NH₄)₃PO₄ is soluble.</h3>
* All Cl⁻, I⁻, Br⁻ are soluble except when are with Ag⁺, Hg₂²⁺, Pb²⁺, Hg₂Cl₂ is <em>insoluble</em>
* Carbonates are insoluble except those with group 1 or ammonium, CdCO₃ is <em>insoluble</em>
* All sulfates are soluble except those with Ca²⁺, Sr²⁺, Ba²⁺, Pb²⁺, Ag⁺. PbSO₄ is <em>insoluble. </em>
Right solution is:
<h3>a. Na₂S and (NH₄)₃PO₄
</h3>
