Final answer:
The formula equation for the reaction between cobalt(II) chloride and sodium hydroxide is CoCl2(aq) + 2 NaOH(aq) → Co(OH)2(s) + 2 NaCl(aq). The complete ionic equation shows all ions in the reaction, while the net ionic equation shows only the ions that participate in forming the cobalt hydroxide precipitate.
Step-by-step explanation:
The student asked to write the correct formula equation, complete ionic equation, and net ionic equation for the reaction between cobalt(II) chloride and sodium hydroxide. The chemical equation for the reactants cobalt(II) chloride and sodium hydroxide forming the products cobalt hydroxide and sodium chloride is as follows:
Formula Equation
CoCl2(aq) + 2 NaOH(aq) → Co(OH)2(s) + 2 NaCl(aq)
Complete Ionic Equation
Co2+(aq) + 2 Cl−(aq) + 2 Na+(aq) + 2 OH−(aq) → Co(OH)2(s) + 2 Na+(aq) + 2 Cl−(aq)
Net Ionic Equation
Co2+(aq) + 2 OH−(aq) → Co(OH)2(s)
To arrive at the net ionic equation, we eliminate the spectator ions, which in this case are the sodium ions (Na+) and the chloride ions (Cl−), leading to the net reaction that shows the formation of cobalt hydroxide precipitate from cobalt(II) ions and hydroxide ions.