Identify each compound as either a Bronsted-Lowry acid or base, Arrhenius acid or base or both. So here in the first one we have carbonic acid. Carbonic acid can dissociate into H+ ions when we place it within an aqueous solution. This would make it an Arrhenius acid. At the same time synthetic can dissolve into H+ ions. When placed into an aqueous solution, it could technically donate that H+ as well, so it also represent a Bronsted-Lowry acid. So here we're going to say it's both an Arrhenius acid and a Bronsted-Lowry acid. So I'll say it's both.
Next we have methylamine. This is a neutral amine. Remember, neutral amines represent weak bases. Because it is a neutral amine it could accept an H+ and therefore represents a Bronsted-Lowry base. However, it is not a metal hydroxide. Dissolving it in an aqueous solution does not allow it to release an OH- from itself. So it would not be an Arrhenius base. So here it is only a Bronsted-Lowry base, which one abbreviate as BLB.
Next we have potassium amide. This represents a strong base. Because it is a base, it could accept an H+ ion from the water molecules around it. Once you place it within an aqueous solution so it can serve as a Bronsted-Lowry base. Again, it is not composed of a metal hydroxide, therefore it doesn't release OH- from its dissolution. So we couldn't say that it is Arrhenius base. So this is just going to be a Bronsted-Lowry base.
Next we have strontium hydroxide. It is the metal hydroxide, so it is an Arrhenius base. It also has the presence of OH-, which could accept an H and therefore it represents a Bronsted-Lowry base. So we're going to say here this is an Arrhenius base plus a Bronsted-Lowry base. So we'll say it's both.
Next we have hydrofluoric acid HF. It could release H+ when dissolved in a solution, so it represents an Arrhenius acid. And because it can release an H ion, it could donate that H ion. So it is also a Bronsted-Lowry acid. So we're going to say it's an Arrhenius acid plus a Bronsted-Lowry acid. So it's both.
And then finally we have calcium hydride. Calcium hydride is a strong base here. The presence of the hydride ion H-, it could accept an H+ ion. So it is a Bronsted-Lowry base, but it is not a metal hydroxide. So we won't say that it represents an Arrhenius base. So here we're just going to say it's a Bronsted-Lowry base and that's how we classify each one of these compounds.