Approximately 1 mL of two clear, colorless solutions, 0.1 M Ba(NO3)2 and 0.1 M Na2SO4, were combined. Upon mixing, a thick milky white precipitate formed. After centrifugation, the solution above the precipitate was found to be clear and colorless. Based on the these observations, determine if a reaction occurred. If so, what is the net ionic equation for the reaction.

Ba²⁺(aq) + SO₄²⁻(aq) ⇒ BaSO₄(s)

Explanation:

Let's consider the molecular equation for the reaction between Ba(NO₃)₂ and Na₂SO₄. This is a double displacement reaction in which BaSO₄ forms a white precipitate.

Ba(NO₃)₂(aq) + Na₂SO₄(aq) ⇒ BaSO₄(s) + 2 NaNO₃(aq)

The complete ionic equation includes all the ions and insoluble species.

Ba²⁺(aq) + 2 NO₃⁻(aq) + 2 Na⁺(aq) + SO₄²⁻(aq) ⇒ BaSO₄(s) + 2 Na⁺(aq) + 2 NO₃⁻(aq)

The net ionic equation includes only the ions that participate in the reaction and insoluble species.

Ba²⁺(aq) + SO₄²⁻(aq) ⇒ BaSO₄(s)

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.