Question

What are the products of the reaction between the aqueous solutions of `"Na"_2"SiO"_3"` and `"Cu"("NO"_3)_2"`?

Answer 1

The product of this reaction is `"CuSiO"_3("s")"`.

Explanation:

The molecular equation is:

`"Na"_2"SiO"_3("aq")+"Cu"("NO"_3)_2("aq")` `rarr` `"CuSiO"_3 + "2NaNO"_3"`

In a double replacement reaction between two ionic compounds in aqueous solution, the cations switch partners with the anions.

In the image below, the cations are red and the anions are blue.

One of the products of a double replacement reaction must be a precipitate (insoluble solid), water (neutralization), or an insoluble gas. We can see that neither water nor a gas is one of the products, so we need to determine whether one of the products is a precipitate. We do this by consulting a solubility table or solubility rules.

We can see that `"NaNO"_3"` is soluble in water because it contains the nitrate ion, `("NO"_3^(-)")`.

`"CuSiO"_3"` is not covered by this table, however it can be found on the solubility table at http://periodic-table-of-elements.org/SOLUBILITY. (It is too big to put it here.) We can see that this compound is insoluble, so it is a precipitate.

Now we can rewrite the molecular equation with the states for the products included.

`"Na"_2"SiO"_3("aq")+"Cu"("NO"_3)_2("aq")` `rarr` `"CuSiO"_3("s") + "2NaNO"_3("aq")"`

Since `"NaNO"_3"` is soluble in water, its ions are dissociated in the water and do not form a discrete compound. So the product of this reaction is the precipitate `"CuSiO"_3"`.

The net ionic equation for a double replacement reaction shows only the ions that reacted and their product.

`"Cu"^(2+)("aq") + "SiO"_3^(2-)("aq")"` `rarr` `"CuSiO"_3("s")"`