Solubility Rules
1. Compounds containing group 1 alkali metals or ammonium [tex]$\left( NH_4^{+}\right)$[/tex] are soluble.
2. Nitrates [tex]$\left( NO_3^{-}\right)$[/tex], chlorates [tex]$\left( ClO_3^{-}\right)$[/tex], perchlorates [tex]$\left( ClO_4^{-}\right)$[/tex], and acetates [tex]$\left( C_2H_3O_2^{-}\right)$[/tex] are soluble.
3. Chlorides [tex]$\left( Cl^{-}\right)$[/tex], bromides [tex]$\left( Br^{-}\right)$[/tex], and iodides [tex]$\left( I^{-}\right)$[/tex] are soluble, except for compounds containing silver [tex]$\left( Ag^{+}\right)$[/tex], mercury [tex]$(I) \left( Hg_2^{2+}\right)$[/tex], and lead [tex]$\left( Pb^{2+}\right)$[/tex].
4. Sulfates [tex]$\left( SO_4^{2-}\right)$[/tex] are soluble, except for compounds containing calcium [tex]$\left( Ca^{2+}\right)$[/tex], strontium [tex]$\left( Sr^{2+}\right)$[/tex], barium [tex]$\left( Ba^{2+}\right)$[/tex], and lead [tex]$\left( Pb^{2+}\right)$[/tex].
5. Hydroxides [tex]$\left( OH^{-}\right)$[/tex], carbonates [tex]$\left( CO_3^{2-}\right)$[/tex], and phosphates [tex]$\left( PO_4^{3-}\right)$[/tex] are insoluble, except for compounds containing group 1 alkali metals and ammonium [tex]$\left( NH_4^{+}\right)$[/tex].

Use the solubility rules and the periodic table to predict the product that will precipitate out in the reaction:
[tex]$
K_2SO_4 (aq) + Ba(NO_3)_2 (aq) \rightarrow ?
$[/tex]

A. [tex]$KNO_3$[/tex]

B. [tex]$Ba(NO_3)_2$[/tex]

C. [tex]$K_2SO_4$[/tex]

D. [tex]$BaSO_4$[/tex]



Answer :

To solve the problem and determine which product will precipitate out, we need to consider the solubility rules provided and the nature of the reactants in the given chemical reaction:

[tex]\[ K_2SO_4(\text{aq}) + Ba(NO_3)_2(\text{aq}) \rightarrow ? \][/tex]

The reactants are potassium sulfate ([tex]\(K_2SO_4\)[/tex]) and barium nitrate ([tex]\(Ba(NO_3)_2\)[/tex]), both in aqueous form. When these compounds react, they undergo a double displacement reaction:
[tex]\[ K_2SO_4(\text{aq}) + Ba(NO_3)_2(\text{aq}) \rightarrow KNO_3(\text{aq}) + BaSO_4(\text{s}) \][/tex]
Let's break it down in detail:

1. Formation of Potassium Nitrate [tex]\(KNO_3\)[/tex]:
- According to Rule 2, nitrates [tex]\((NO_3^-)\)[/tex] are always soluble. Therefore, potassium nitrate [tex]\(KNO_3\)[/tex] will dissolve in water and remain in an aqueous form.

2. Formation of Barium Sulfate [tex]\(BaSO_4\)[/tex]:
- According to Rule 4, sulfates [tex]\((SO_4^{2-})\)[/tex] are generally soluble except when they are combined with barium [tex]\((Ba^{2+})\)[/tex], calcium [tex]\((Ca^{2+})\)[/tex], strontium [tex]\((Sr^{2+})\)[/tex], or lead [tex]\((Pb^{2+})\)[/tex]. In this case, the sulfate is combining with barium:
[tex]\[ Ba^{2+} + SO_4^{2-} \rightarrow BaSO_4 \][/tex]
- Barium sulfate [tex]\(BaSO_4\)[/tex] is insoluble in water, meaning it will form a precipitate.

After analyzing the reaction, the precipitate that forms is barium sulfate [tex]\(BaSO_4\)[/tex].

Let's match this to the answer choices:

- A. [tex]\(KNO_3\)[/tex] – This compound is soluble and does not precipitate.
- B. [tex]\(Ba(NO_3)_2\)[/tex] – This is a reactant, not a product, and it remains in solution.
- C. [tex]\(K_2SO_4\)[/tex] – This is a reactant, not a product.
- D. [tex]\(BaSO_4\)[/tex] – This is the correct answer: the product that precipitates out.

Therefore, the correct answer is:

[tex]\[ \boxed{D} \][/tex]