Question #f9544

1 Answer
Jun 8, 2016

Answer:

Yes, the reaction is possible.

Explanation:

You're dealing with a double replacement reaction in which ammonium carbonate, #("NH"_4)_2"CO"_3#, and cobalt(II) chloride, #"CoCl"_2#, react to form cobalt(II) carbonate, #"CoCO"_3#, and insoluble solid, and aqueous ammonium chloride, #"NH"_4"Cl"#.

Both ammonium carbonate and cobalt(II) chloride are soluble in aqueous solution, which means that you can write them as

#("NH"_ 4)_ 2 "CO"_ (3(aq)) -> 2"NH"_ (4(aq))^(+) + "CO"_ (3(aq))^(2-)#

and

#"CoCl"_ (2(aq)) -> "Co"_ ((aq))^(2+) + 2"Cl"_ ((aq))^(-)#

When the two solutions are mixed, the cobalt(II) cations, #"Co"^(2+)#, will combine with the carbonate anions ,#"CO"_3^(2-)#, to form the insoluble solid which then precipitates out of solution.

The complete ionic equation for this reaction will look like this

#2"NH"_ (4(aq))^(+) + "CO"_ (3(aq))^(2-) + "Co"_ ((aq))^(2+) + 2"Cl"_ ((aq))^(-) -> "CoCO"_ (3(s)) darr + 2"NH"_ (4(aq))^(+) + 2"Cl"_ (2(aq))^(-)#

As you can see, some of the ions are present on both sides of the equation. These ions are called spectator ions and can be removed from the equation

#color(red)(cancel(color(black)(2"NH"_ (4(aq))^(+)))) + "CO"_ (3(aq))^(2-) + "Co"_ ((aq))^(2+) + color(red)(cancel(color(black)(2"Cl"_ ((aq))^(-)))) -> "CoCO"_ (3(s)) darr + color(red)(cancel(color(black)(2"NH"_ (4(aq))^(+)))) + color(red)(cancel(color(black)(2"Cl"_ ((aq))^(-))))#

to get the net ionic equation

#"Co"_ ((aq))^(2+) + "CO"_ (3(aq))^(2-) -> "CoCO"_ (3(s)) darr#

It's worth noting that cobalt(II) carbonate is light purple in color.

https://www.flickr.com/photos/37388341@N00/1508161448

Therefore, you will have

#("NH"_ 4)_ 2 "CO"_ (3(aq)) + "CoCl"_ (2(aq)) -> "CoCO"_ (3(s)) darr + 2"NH"_ 4"Cl"_ ((aq))#