What is the anion of this formula? Please help if possible. Thank you!

Question

When NaCl dissociates in water, what is the anion? 

When Ca(OH)₂ dissociates in water, what is the anion? 

Answer 1

Whenever dissociation comes up, just think about splitting the compound into its positive and negative components. NaCl will split into Na⁺ (cation) and Cl^- (anion), Ca(OH)₂ will split into Ca²⁺ (cation) and 2 OH^- (anion).

Keep in mind that like dissolves like: polar solvents dissolve polar compounds, and nonpolar compounds dissolve nonpolar compounds.