Video Transcript
What is the net ionic equation for
the reaction between barium nitrate and a metal sulfate, which is used as a test for
the sulfate anion? (A) NO32− aqueous plus SO42−
aqueous gives SO3− aqueous plus NO2 gas plus O2 gas. (B) Ba solid plus SO42− aqueous
gives BaSO4 solid. (C) Ba2+ aqueous plus SO42− aqueous
gives BaSO4 solid. (D) Ba2+ aqueous plus SO42− aqueous
gives SO2 gas plus O2 gas plus Ba solid. (E) Ba(NO3)2 solid plus H2SO4
aqueous gives BaSO4 solid plus two HNO3 aqueous.
In this question, we need to
consider the reaction between barium nitrate, which is a soluble barium salt, and a
metal sulfate, which can be represented as MSO4 (aq), since it also must be
soluble. Since we are going to show a net
ionic equation for this reaction, only the ions reacting will be shown. Any spectator ions will be
removed. Spectator ions are those that do
not change in the reaction at all.
When one mole of barium nitrate is
dissolved in water, it yields one mole of barium two plus ions and two moles of
nitrate ions. These are aqueous ions. When our soluble metal sulfate,
represented as MSO4, is added to water, it will yield one mole of M2+ ions aqueous
and one mole of SO42− ions, also aqueous.
Now we have a complete list of
reactant ions, we can consider what happens to them during the course of this
reaction. The barium ions react with the
sulfate ions to form insoluble barium sulfate. This is written BaSO4 brackets
s. The metal ions and nitrate ions
form a soluble nitrate salt. As these ions are soluble, they can
be added to the list of products in our ionic equation. The nitrate ions and metal ions are
in fact spectator ions. And they can be removed from this
ionic equation. This produces the net ionic
equation which exactly matches answer (C) with the correct state symbols.
