Write the balanced net ionic equation for the reactions that occur when the given aqueous solutions are mixed. Include the physical states. A. nitric acid, HNO 3 , and calcium hydroxide, Ca ( OH ) 2 net ionic equation: B. lead(II) nitrate, Pb ( NO 3 ) 2 , and potassium iodide, KI

a. 2 H⁺ (aq) + 2 OH⁻ (aq) → 2H₂O(l)

b. Pb²⁺(aq) + 2I⁻(aq) → PbI₂(s)

Explanation:

First of all, we must determine if the reactants produce precipitates:

A. HNO₃, Ca(OH)₂

B. Pb(NO₃)₂, KI

A. This is a neutralization reaction:

Acid + Base → Water and Salt

The net ionic equation shows, that water is produced

We dissociate the compounds:

HNO₃  →  H⁺(aq)  +  NO₃⁻(aq)

Ca(OH)₂(aq) → Ca²⁺(aq) + 2OH⁻(aq)

Ionic complete equation:

2H⁺(aq) + 2NO₃⁻(aq)  +  Ca²⁺(aq) + 2OH⁻(aq) → Ca²⁺(aq) + 2NO₃⁻(aq) + H₂O(l)

Net ionic equation:   2 H⁺ (aq) + 2 OH⁻ (aq) → H₂O(l)

B. Pb(NO₃)₂, KI

We dissociate: Pb(NO₃)₂ (aq) →  Pb²⁺(aq) + 2NO₃⁻(aq)

KI(aq) →  K⁺(aq) + I⁻(aq)

Salts from nitrate are soluble but, when the iodide reacts, it can make a lead iodide precipitate

Ionic complete equation:

Pb²⁺(aq) + 2NO₃⁻(aq)  +  K⁺(aq) + 2I⁻(aq) → K⁺(aq) + 2NO₃⁻(aq) +PbI₂(s)

Net ionic equation: Pb²⁺(aq) + 2I⁻(aq) → PbI₂(s)

We cancel the repeated ions