Is this passage from Chapter 15 of To Kill a Mockingbird an example of dramatic irony? "Link, that boy might go to the chair, but he's not...

As you already know, dramatic irony results when we as the readers actually know more about what's going on than one or more of the characters do.

Because Scout is so young and naive throughout this novel, and because her older self is narrating the story, we experience lots of dramatic irony throughout the novel. Any time we know what's going on and Scout doesn't, that's dramatic irony in play.

So let's take a look at that quote from Chapter 15 and make some sense of it. Assuming we've been paying sharp attention as readers, what is it that we know that Scout doesn't know?

That conversation takes place at the Finch home. Mr. Heck Tate and Mr. Link Deas, among other men, have come to talk to Atticus. The curious kids (Scout, Jem, and their friend Dill) spy on the conversation through the window.

The men are worried that the townspeople will get drunk and violent toward Tom while he is being moved to the county jail.

When Link asks Atticus why he even took on such a terrible case, that's when Atticus responds that Tom might be put to death, but people will hear the truth first.

And what Scout doesn't realize--but we do realize--is what the truth is. Tom is innocent. He didn't commit the rape he's been accused of. Further, we know that Atticus is acknowledging that he could lose and that his client could die, and still he’s going to make the truth known, because it’s the right thing to do. Of course, Scout doesn't understand the situation right then. She's a small child, curious as can be and eager to pay attention, but she doesn't have all the details of the trial.