"The Story of an Hour" is full of suspense, irony, contrast, and paradox.
This story's main character is told that her husband has passed away. Generally, a first emotion for a marriage that has been long-lasting is grief or pain. For this character, she is sensing an amazing freedom, an exact contrast to the aforementioned feelings:
There would be no one to live for during those coming years; she would live for herself. There would be no powerful will bending hers in that blind persistence with which men and women believe they have a right to impose a private will upon a fellow-creature.
An irony which reveals itself through these words occurs with the idea of marriage being corporate. Generally, true love assumes that part of the purpose of living together is to live for each other. She is weary of that type of relationship.
Another contrast occurs as Louise Mallard's sister insists that she is going to make herself ill (supposedly from grief that comes in through the open window), yet the narration of the story reports that Louise is "drinking in a very elixir of life". The contrast between sickness and health comes in the words ill and elixir of life.
Paradox can be seen in the typical expectations for death. Near the end, although this woman should be grieving, she is experiencing
"a feverish triumph in her eyes, and she carried herself unwittingly like a goddess of Victory."
Often, we speak of death having victory or conquering us. In this instance, it is Mrs. Louise Mallard who feels she has been the Victor over death.
All of these literary elements demontrate themselves through Chopin's clear and precise diction.
Hope that helps.
Do not forget to consider the title. The whole episode takes place in an hour.
Look at Louise's last name. Mallards are ducks, and I believe they are supposed to mate for life. That's a nice piece of symbolism there.