When 0.2 M sodium hydroxide and 0.2 M barium nitrate are mixed, a precipitate is formed. What is the net ionic equation for the formation of this precipitate?

Question

Quizplus · Accepted Answer

The net ionic equation shows only the species that participate in the reaction and undergo a chemical change. First, we need to write the balanced molecular equation:

NaOH(aq) + Ba(NO3)2(aq) → Ba(OH)2(s) + 2NaNO3(aq)

Next, we write the complete ionic equation by breaking up all the soluble compounds into their constituent ions:

Na+(aq) + OH-(aq) + Ba2+(aq) + 2NO3-(aq) → Ba(OH)2(s) + 2Na+(aq) + 2NO3-(aq)

Finally, we cancel out the spectator ions (Na+ and NO3-) that appear on both sides of the equation to obtain the net ionic equation:

Na+(aq) + OH-(aq) + Ba2+(aq) → Ba(OH)2(s)

This shows that the formation of a precipitate (Ba(OH)2) is due to the reaction between the hydroxide ion (OH-) from sodium hydroxide and the barium ion (Ba2+) from barium nitrate. Choice D correctly represents this net ionic equation.

When 02 M Sodium Hydroxide and 0