w00t for Sonata form.
The piece starts right in with group 1, which is only 8 measures long. After a half cadence in e minor, Haydn begins to restate the main theme from Gr. 1 but it soon begins to move to the relative major, G, with an IAC in that key in measure 14. This section, from measures 9-28, is a transition to Group two. It ends with a PAC in D major, which is the dominant of G major, so, after a fermata, when Group 2 begins in G major, it makes tonal sense.
Group 2 is very similar to Group 1, in that the main theme is short (six measures long). Again, Haydn states it, ending with a PAC in G major, then pausing and beginning a restatement of the theme. This time, however, it does not modulate, which keeps this piece true to sonata form, ending with a PAC in G major in measure 42. The cadence is extended until measure 45.
The development begins with material from Group 1, though now it's in a minor. This lasts for 5 measures, and then the piece pauses before continuning on to develop the material from the first transition (between Groups 1 and 2). In measure 71, Haydn begins to redevelop the theme from Group 1. However, it's inverted - the right hand begins each call-and-response. This section ends in measure 78 with a half cadence in e minor, bringing us back to a strong sense of tonic for the recapitulation.
Group 1 comes back in measure 79, though this time it's not completely restated. Instead, Haydn begins a transition which lasts until measure 94, ending with a pause on a PAC in B major, preparing the listener for e minor in the recap of Group 2 material, which begins in measure 95.
Group two, modified, is recapitulated from m. 95 to 100, ending with a PAC in e minor and pausing before Haydn develops the material that had previously been the transition between group 2 and the development. This concludes with a PAC in e minor in measure 109, which begins a long terminative section. One could argue that the terminative section doesn't begin until later, perhaps measure 118, but I hear it as beggining in measure 108 because the long harmonic progression that follows is just leading back to e minor - nothing new comes of it.