In Act II, Tosca breaks our hearts when she reflects on her fate and asks why God has abandoned her.
Here's a translation to guide your listening:
I lived for art, I lived for love, I never harmed a living soul!
With a discreet hand, I relieved all misfortunes I encountered.
Always with sincere faith, my prayer rose to the holy tabernacles.
Always with sincere faith, I decorated the altars with flowers.
In this hour of grief, why, why, Lord, why do you reward me thus?
I donated jewels to the Madonna's mantle, and offered songs to the stars and to heaven, which thus did shine with more beauty.
In this hour of grief, why, why, Lord, ah, why do you reward me thus?