queous solution of sodium phosphate (Na3PO4). Adding which compound to the solution will cause a phosphate compound to precipitate?

To identify which compound can cause a phosphate compound to precipitate from a solution of sodium phosphate (Na3PO4), we need to look for a compound that can form an insoluble (or low solubility) phosphate compound in the solution.

1. Start by examining the solubility rules for common compounds. These rules provide information on which compounds are soluble or insoluble in water.

2. Look for compounds that contain cations (positively charged ions) that can form insoluble phosphate compounds. In this case, we are interested in compounds that have cations capable of forming stable phosphate precipitates.

3. One common compound that can cause a phosphate compound to precipitate is calcium chloride (CaCl2). When added to a solution containing phosphate ions (PO4^3-), the calcium ions (Ca^2+) can react with the phosphate ions to form solid calcium phosphate (Ca3(PO4)2), which is insoluble in water.

The balanced equation for the reaction can be written as:

3 Ca^2+ (aq) + 2 PO4^3- (aq) -> Ca3(PO4)2 (s)

So, adding calcium chloride (CaCl2) to the aqueous solution of sodium phosphate (Na3PO4) will cause the formation of a phosphate compound (calcium phosphate, Ca3(PO4)2) to precipitate.