Question

How do you write balanced, net ionic equations for 1). `"Cu"^(2+) and text(F)^-`, and `"Cu"^(2+) and "Cl"^-`?

Aqueous copper(II) sulfate solution is blue in color. When aqueous potassium fluoride is added, a green precipitate is formed. When aqueous potassium chloride is added instead, a bright-green solution is formed. (Use the lowest possible coefficients. Include states-of-matter under SATP conditions in your answer.)

Answer 1

Here's what I get.

Explanation:

1) `"Cu"^"2+"` and `"F"^"-"`

Molecular equation:

`"CuSO"_4"(aq)" + "2KF(aq)" → "CuF"_2"(s)" + "K"_2"SO"_4"(aq)"`

Ionic equation

`"Cu"^"2+""(aq)" + "SO"_4"(aq)" + "2K"^"+""(aq)" + "2F"^"-""(aq)"`

`→ "CuF"_2"(s)" + "2K"^"+""(aq)" + "SO"_4^"2-""(aq)"`

Net ionic equation

`"Cu"^"2+""(aq)" +color(red)(cancel(color(black)( "SO"_4"(aq)"))) + color(red)(cancel(color(black)("2K"^"+""(aq)"))) + "2F"^"-""(aq)"`

`→ "CuF"_2"(s)" + color(red)(cancel(color(black)("2K"^"+""(aq)"))) + color(red)(cancel(color(black)("SO"_4^"2-""(aq)")))`

`underbrace("Cu"^"2+""(aq)")_color(red)("blue") + "2F"^"-""(aq)" → underbrace("CuF"_2"(s)")_color(red)("green")`

2) `"Cu"^"2+""(aq)"` and `"Cl"^"-""(aq)"`

Molecular equation

`"CuSO"_4"(aq)" + "4KCl(aq)" → "K"_2"CuCl"_4"(aq)" + "K"_2"SO"_4"(aq)"`

Ionic equation

`"Cu"^"2+""(aq)" + "SO"_4^"2-""(aq)" + "4K"^"+""(aq)" + "4Cl"^"-""(aq)"`

`→ "2K"^"+""(aq)" + "CuCl"_4^"2-""(aq)" + "2K"^"+""(aq)" + "SO"_4^"2-""(aq)"`

Net ionic equation

`"Cu"^"2+""(aq)" + color(red)(cancel(color(black)("SO"_4^"2-""(aq)"))) + color(red)(cancel(color(black)("4K"^"+""(aq)"))) + "4Cl"^"-""(aq)"`

`→ color(red)(cancel(color(black)("2K"^"+""(aq)"))) + "CuCl"_4^"2-""(aq)" + color(red)(cancel(color(black)("2K"^"+""(aq)"))) + color(red)(cancel(color(black)("SO"_4^"2-""(aq)")))`

`underbrace("Cu"^"2+""(aq)")_color(red)("blue") + "4Cl"^"-""(aq)" → underbrace("CuCl"_4^"-""(aq)")_color(red)("green")`