This comes from Act II, Scene III of Mozart's Don Giovanni. Left alone, and having been betrayed yet again, Elvira struggles with the realization that Don Giovanni is going to be punished by heaven and not by her hand. The recitative and aria shows how torn she is by feelings of betrayal and deceit, and then her concern for his well-being. This is a coloratura aria which means one with rapid scales and arpeggios in the voice, which in this case convey the intensity of her feelings.
The whole aria is in the form A- B (dominant)- A - C (parallel minor)- A. This exerpt comes from the first A section after the recitative. It is very simply laid out with a simple Antecedent phrase and answered by a more jarring and harmonically complicated consequent phrase. Both end in authentic cadences with slightly different voicing.
The soprano has a beautiful melody, only straying from the harmonic outlines on words like suffering, vengence, fatal, and other such dramatic soprano tendencies. Overall a very dramatic piece describing the dual emotions that every soprano must face in every opera. :-)
Rock me Amadeus.