What volume in 'Naruto' is Tobi's mask broken?

Tobi's mask is broken in "Naruto" Volume 32. During the battle between Tobi and Kakashi, Tobi's mask shatters, revealing his true identity as Obito Uchiha. This moment is significant as it uncovers a pivotal twist in the story and ties back to key themes of loss and redemption in the series.