This piece is in sonata-rondo form, though I feel it leans more towards the rondo feel rather than sonata, primarily because the C section doesn't develop previous motives from the movement. Instead, it presents entirely new material, which is in a very different feel from the rest of the movement, which is very stormy and passionate.
It does adhere, however, to the A B A C A B A format. I refer to the different sections with a number after them to indicate which repetition of the section I'm talking about.
The piece begins right away with A1, which has two themes (Aa and Ab). Aa is made up of one phrase which ends with a PAC in m. 8 and is extended to m. 12, where it ends with another PAC in c minor. This begins Ab, which lasts only five measures until m. 18, ending with a forceful PAC in c minor - A is closed tonally. There is a transition in mm. 18-25, which modulates to Eb major and therefore begins the B section.
Once Eb has arrived in m. 25, it is still not firmly established - Beethoven plays around with eb minor just five bars later. Therefore, I hear this as still transitional material. However, it's important to address the measures 25-29 (x) separately because they contain thematic material that will be developed later.
B has two themes (Ba, and Bb). Ba begins in m. 37 and is defined by triplets played in a call-and-response manner between the right and left hands. It ends with a PAC in m. 42, and right away Bb begins. This theme ends with an IAC in Eb major in m. 51 and leads back into Ba, making the B section a small rounded binary form.
The return of Ba is not ended with a PAC in Eb major as it did the first time. Now, it leads into a transition (mm. 56-60), which ends in a HUGE HC in c minor, bringing the return of A (A2).
A2 is replayed much as it is in the beginning - Aa goes from measure 61- 73, and Ab picks up there and finishes with a very strong PAC in c minor in m. 78.
At this point, the C section begins in Eb major. There is a completely new theme - it is characterized by the soft, smooth playing of half notes. It is made up principally of four half notes followed by a quarter-note line that brings it to a close with n IAC in Eb major every four bars. This motive is manipulated - inverted, played in octaves, played in the left hand, etc. It is played a total of four times before a transition begins in measure 95 and lasts all the way until measure 120, ending with a huge half cadence in c minor (it modulated along the way).
A returns (A3). This time, however, after Aa, Ab doesn't come back. Instead, Aa is developed in mm. 128-132, and then x, the transition between A1b and B1a comes back. It's dolce-ness is a nice contrast at this point. As in the beginning, it leads to Ba (this time B2a), which is now in G major. B2a is followed by B2b, which begins in m. 153 and leads into a transtion (m. 162) which leads us to the return of A (A4).
The return of A lacks Ab again, but instead goes into a transition, which leads to a terminative section that begins in 182. This section is very stormy, and lasts until the end of the piece (obviously). There is a REALLY interesting moment in Ab major in mm. 202-205 - after a huge HC in f, a quiet, calm melody cuts in and is played twice. The piece concludes with a huge descending scale, ending with a fiery PAC in c minor that seems all the more furious because of the quiet moment just bars before.