Question

Identify the equations that show ionization. Check all that apply.

Upper N a upper C l (s) right arrow upper N a superscript plus (a q) plus upper C l superscript minus (a q).

Upper H upper C l (g) plus upper H subscript 2 upper O (l) right arrow upper C subscript 3 upper O superscript plus (a q) plus upper C l superscript minus (a q).

Upper O subscript 2 (g) right arrow upper O subscript 2 (a q).

Upper C upper O subscript 2 (g) plus 2 upper H subscript 2 upper O (l) right arrow upper H upper C upper O subscript 3 superscript minus (a q) plus upper H subscript 3 upper O superscript plus (a q).

Upper C a upper C l subscript 2 (s) right arrow upper C a superscript 2 plus (a q) plus 2 upper C l superscript minus (a q).

Answer 1

The equations that show ionization are: 1, 2, 4, and 5.

- 1) NaCl(s) → Na+(aq) + Cl-(aq): ionic solid dissociates into ions (ionization/dissociation).
- 2) HCl(g) + H2O(l) → H3O+(aq) + Cl-(aq): HCl ionizes in water to give hydronium and chloride.
- 4) CO2(g) + 2 H2O(l) → HCO3-(aq) + H3O+(aq): CO2 reacts with water to produce ions (bicarbonate and hydronium).
- 5) CaCl2(s) → Ca2+(aq) + 2 Cl-(aq): ionic solid dissociates into ions.

3) O2(g) → O2(aq) is just physical dissolution (no ions formed), so it is not ionization.