Video Transcript
The following equation shows four
chemical reactions that form sulfate salts. BaCl2 aqueous plus MgSO4 aqueous
yields MgCl2 aqueous plus BaSO4 solid. Mg solid plus H2SO4 aqueous yields
MgSO4 aqueous plus H2 gas. Two NaOH aqueous plus H2SO4 aqueous
yields Na2SO4 aqueous plus two H2O liquid. Two NH3 aqueous plus H2SO4 aqueous
yields (NH4)2(SO4) aqueous. Which of the sulfate salts is
insoluble?
This question is asking us to
identify a chemical reaction that forms an insoluble sulfate salt. Before we begin this problem, let
us first review the parts of a chemical equation. We need to discuss that chemicals
that start within a chemical reaction called reactants are located on the left-hand
side of the arrow in a chemical equation. Chemicals that are formed during a
chemical reaction are called products and are found to the right of the arrow within
a chemical equation. Since we need to find an insoluble
sulfate salt that was formed, we need to only look at the sulfates on the right-hand
side of the chemical equation, which would be the product side.
Now that we know which side of the
chemical equation we will be focusing on, now let us identify a sulfate salt. The sulfate salt is SO4 2−. And a sulfate salt is a salt that
has a cation with SO4 as the anion. Therefore, we are only looking at
BaSO4, MgSO4, Na2SO4, and (NH4)2(SO4) as potential sulfate salts that are
insoluble.
Since we have identified the
sulfate salts in each reaction, now we can review how to identify an insoluble
compound in a chemical equation. The term insoluble refers to a
chemical that cannot dissolve in a substance. When looking at the states of
matter in a chemical equation, we need to discuss that “g” means the chemical or
element is in a gaseous state. “l” is a liquid, such as water,
bromine, or mercury. “aq” means the substance has been
dissolved in water and is an aqueous solution and is therefore soluble. And “s” means the chemical is a
solid or insoluble. The only sulfate salt that has an s
for solid is BaSO4.
Therefore, BaSO4 is the only
insoluble salt formed within the four chemical equations.
