Question

which equation describes the dissociation of na₂co₃ as it dissolves in water? na₂co₃ → 2na⁺ + co₃²⁻; na₂co₃ → na₂o + co₂; na₂co₃ → na⁺ + naco₃⁻

Explanation:

To determine the correct dissociation equation of $\ce{Na_{2}CO_{3}}$ in water, we analyze the ionic composition. Sodium carbonate ($\ce{Na_{2}CO_{3}}$) is an ionic compound composed of $2$ $\ce{Na^{+}}$ ions and $1$ $\ce{CO_{3}^{2-}}$ ion. When it dissolves in water, it dissociates into its constituent ions.

• The first option $\ce{Na_{2}CO_{3}

ightarrow 2Na^{+} + CO_{3}^{2-}}$ shows the correct dissociation into two sodium ions and one carbonate ion.

• The second option $\ce{Na_{2}CO_{3}

ightarrow Na_{2}O + CO_{2}}$ is a decomposition reaction, not a dissociation in water.

• The third option $\ce{Na_{2}CO_{3}

ightarrow Na^{+} + NaCO_{3}^{-}}$ is incorrect as it does not represent the proper dissociation of the carbonate ion.

Answer:

A. $\ce{Na_{2}CO_{3}
ightarrow 2Na^{+} + CO_{3}^{2-}}$