Question #d3b6a

1 Answer
Jan 10, 2017

Here's what I got.

Explanation:

Barium nitrate, "Ba"("NO"_3)_2Ba(NO3)2, and sodium fluoride, "NaF"NaF, are soluble ionic compounds, which means that they exist as ions in aqueoues solutions.

"Ba"("NO"_ 3)_ (2(aq)) -> "Ba"_ ((aq))^(2+) + 2"NO"_ (3(aq))^(-)Ba(NO3)2(aq)Ba2+(aq)+2NO3(aq)

"NaF"_ ((aq)) -> "Na"_ ((aq))^(+) + "F"_ ((aq))^(-)NaF(aq)Na+(aq)+F(aq)

When two aqueous solutions of barium nitrate and sodium fluoride are mixed, two ionic compounds are formed

  • barium fluoride, "BaF"_2BaF2, an insoluble ionic compound that precipitates out of solution
  • sodium nitrate, "NaNO"_3NaNO3, a soluble ionic compound that exists as ions in the resulting solution

You can write the unbalanced chemical equation that describes this double replacement reaction like this

"Ba"("NO"_ 3)_ (2(aq)) + "NaF"_ ((aq)) -> "BaF"_ (2(s)) darr + "NaNO"_ (3 (aq))Ba(NO3)2(aq)+NaF(aq)BaF2(s)+NaNO3(aq)

To balance this chemical equation, add a coefficient of 22 to sodium fluoride

color(darkgreen)(ul(color(black)("Ba"("NO"_ 3)_ (2(aq)) + 2"NaF"_ ((aq)) -> "BaF"_ (2(s)) darr + "NaNO"_ (3 (aq)))))

Now, you can start from the balanced chemical equation and write the complete ionic equation

"Ba"_ ((aq))^(2+) + 2"NO"_ (3(aq))^(-) + 2 xx ["Na"_ ((aq))^(+) + "F"_ ((aq))^(-)] -> "BaF"_ (2(s)) darr + 2 xx ["Na"_ ((aq))^(+) + "NO"_ (3(aq))^(-)]

This is equivalent to

"Ba"_ ((aq))^(2+) + 2"NO"_ (3(aq))^(-) + 2"Na"_ ((aq))^(+) + 2"F"_ ((aq))^(-) -> "BaF"_ (2(s)) darr + 2"Na"_ ((aq))^(+) + 2"NO"_ (3(aq))^(-)

In order to get the net ionic equation, you must remove the spectator ions, i.e. the ions that are present on both sides of the equation.

"Ba"_ ((aq))^(2+) + color(red)(cancel(color(black)(2"NO"_ (3(aq))^(-)))) + color(red)(cancel(color(black)(2"Na"_ ((aq))^(+)))) + 2"F"_ ((aq))^(-) -> "BaF"_ (2(s)) darr + color(red)(cancel(color(black)(2"Na"_ ((aq))^(+)))) + color(red)(cancel(color(black)(2"NO"_ (3(aq))^(-))))

This will get you

color(darkgreen)(ul(color(black)("Ba"_ ((aq))^(2+) + 2"F"_ ((aq))^(-) -> "BaF"_ (2(s)) darr)))