1, protonic acid and Lewis acid are two different concepts in acid-base theory. Protonic acid comes from acid-base proton theory, which holds that the substance that can give protons is acid and the substance that can accept protons is alkali. Lewis acid comes from the theory of acid-base electrons. It is considered that the substance that can receive electron pairs is acid and the substance that can give electron pairs is alkali.

CH5+ is a proton acid because it can provide proton H+ to form CH4.

2, too many, you can find some real questions or simulation questions to do. Generally speaking, it is organic, crystal, inorganic inference, element calculation, equilibrium calculation (possibly electrochemistry), valence bond theory and so on.

3. It is enough to know that "the highest valence hydrates of the three main groups of 5, 6 and 7 are very oxidizing", such as HBRo4 > HCLO4 > H5IO6, H2SeO4>H2SO4 (in fact, H2SO4 is the only single acid that can dissolve Au and Pt), and H3AsO4>H3PO4.

H2PO4- is acidic and HPO42- is alkaline. In oxyacid, there are at least two non-hydroxyl oxygen groups in strong acid; In the case of strong alkali, there are common hydroxides of alkali metals and alkaline earth metals and quaternary ammonium bases (except Be and Mg). In fact, the strong acid and alkali involved in the competition (especially in the preliminary competition) are basically common. ...