In "The Story of an Hour," what are three examples of dramatic irony?

There are several types of irony. Dramatic irony is the type of irony in which the audience or reader knows more about events or people than the characters in the story. Dramatic irony is present in "The Story of an Hour." One example occurs after Louise has been told that her husband has been killed. She excuses herself to her room, and she is presumably grieving the loss of her loved one. Josephine assumes this as well, and she implores to be let into the room in order to console Louise.

Josephine was kneeling before the closed door with her lips to the keyhole, imploring for admission. "Louise, open the door! I beg; open the door—you will make yourself ill. What are you doing, Louise? For heaven's sake open the door."

This moment is a good example of dramatic irony because the reader knows by this point that Louise is definitely not sad about her husband's death. She is sad to a certain extent, but she is more excited about the possibility of living out the rest of her life doing what she wants to do. She is "free."
The very end of the story is dramatic irony as well. The doctors claim that Louise died of a "joy that kills." Everybody believes that she was so happy to see her husband alive that she died from being too happy. Again, the reader knows different. We know that Louise essentially died of depression and heartache.
I don't think a third, prominent example of dramatic irony can be clearly identified in this story; however, there are clear examples of situational and verbal irony in the story. Situational irony is when something happens that is at odds with what is expected to happen. This kind of irony is clear at two points in this story. Louise is told that her husband was killed, and she is happy. Readers don't expect that at all. We expect her to be sad. We also don't expect her to die in the end of the story. When we find out that her husband is alive, we expect her to be sad and fake her happiness. As for verbal irony, I've always liked the opening and closing lines of the story. Readers are told that Louise has "heart trouble" in the opening line of the story. The story closes by reminding readers of this heart affliction.

When the doctors came they said she had died of heart disease . . .

When the story begins, readers have no reason to suspect that the heart trouble is anything other than biologically related; however, by the end of the story, we recognize that the "heart" condition may be an emotional heart condition. Her heart and soul are suffering from the repression that exists within her marriage.