Ionic Equation

Ionic equations

Ionic equations are chemical equations where only the ions involved in the reaction are shown, while spectator ions (those that do not participate in the reaction) are omitted.

Steps for writing ionic equations

1. Balance the Chemical Equation. Ensure the number of atoms for each element is equal on both sides of the equation.
2. Split Ionic Compounds into Ions.
   1. Reactants: Split all solid and soluble ionic compounds into individual ions.
   2. Products: Split only soluble ionic compounds into ions. Keep solids, liquids, and gases intact.
3. Identify and Omit Spectator Ions. Spectator ions appear on both sides of the equation in the same form. They do not change during the reaction.
4. Write the Ionic Equation. Include only the ions and molecules directly involved in the reaction.

Example: reaction of sodium chloride and silver nitrate

Step 1: Write and Balance the Equation

NaCl(aq) + AgNO3(aq) → NaNO3(aq) + AgCl(s)

Step 2: Split Into Ions

1. Reactants: $Na^+(aq) + Cl^-(aq) + Ag^+(aq) + NO_3^-(aq)$
2. Products: $Na^+(aq) + NO_3^-(aq) + AgCl(s)$

Step 3: Omit Spectator Ions

• Spectator ions: $Na^+$ and $NO_3^-$

Step 4: Write the Ionic Equation

Ag+(aq) + Cl-(aq) → AgCl(s)

Example: neutralization reaction between hydrochloric acid and sodium hydroxide

Step 1: Write and Balance the Equation

HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)

Step 2: Split Into Ions

1. Reactants: $H^+(aq) + Cl^-(aq) + Na^+(aq) + OH^-(aq)$
2. Products: $Na^+(aq) + Cl^-(aq) + H_2O(l)$

Step 3: Omit Spectator Ions

• Spectator ions: $Na^+$ and $Cl^-$

Step 4: Write the Ionic Equation

H+(aq) + OH-(aq) → H2O(l)