In what chapter was the Tom Robinson case in the novel To Kill a Mockingbird?

The Tom Robinson trial begins in Chapter 17 and ends in Chapter 21.

Chapter 17: Sheriff Tate is the first person called to the witness stand. Atticus thoroughly questions him regarding the location of Mayella's injuries. Tate says that Mayella's right side of her face was badly beaten and was predominately bruised. The next witness to come to the stand is Bob Ewell. The prosecutor, Mr. Gilmer, asks Bob to explain what happened on the night of November 21st in his own words. Bob claims that he heard his daughter scream and says, "I seen that black nigger yonder ruttin' on my Mayella!" (Lee 231) Ewell tells Judge Taylor he saw Tom having intercourse with his daughter. During Atticus' cross-examination, Bob confirms Sheriff Tate's testimony that Mayella's right eye was bruised. Atticus then asks Bob to write his signature on a piece of paper. Atticus does this to show the jury that Bob is left-handed, which suggests that he could have possibly beaten Mayella.

Chapter 18: Mayella Ewell takes the witness stand. She testifies that Tom Robinson assaulted and raped her. The audience learns about Mayella's lonely, pitiful life taking care of her siblings and living with an abusive father. Mayella seems confused and cannot recount whether Tom beat her or not. Her testimony seems fabricated, and she refuses to answer any of Atticus' questions regarding where the children were during the assault and who she called for while she was being assaulted.

Chapter 19: Tom Robinson takes the witness stand. He tells Atticus that he was familiar with Mayella because he helped her plenty of times with her chores. Tom says that one day she asked him to fix an old door that kept falling off the hinges. He claims that while he was inside the house, Mayella grabbed him around his waist and kissed him. Tom says that he became scared and ran out of the house. Mr. Gilmer cross-examines Tom and Tom admits that he helped Mayella because he felt sympathy for her. This comment does not sit well with the jury and Gilmer proceeds to talk down to Tom.

Chapter 20: Atticus gives his closing remarks and begs the jury to judge Tom based off of the testimonies and evidence presented. He urges them to look past the fact that Tom is black and encourages them not to be swayed by their prejudiced beliefs.

Chapter 21: At the end of the chapter, Judge Taylor reads the verdict. Tom Robinson is found guilty of raping and assaulting Mayella Ewell. Atticus walks quickly down the middle aisle to exit the courtroom once the verdict is read.