(1) According to the chemical formula C6H7KO2, it is composed of four elements: C, H, K, and O; the mass ratio of the three elements C, H, and O in sorbic acid = (12×6) : (1×8): (16×2)=9:1:4;

(2) According to the relative molecule mass, which is the sum of the relative atomic masses of the atoms that make up the molecule, we can get Yamanashi The relative molecular mass of potassium acid is: 12×6 1×7 39 16×2=150; according to the mass fraction of a certain element in the compound potassium = the relative atomic mass of the atom × the number of atoms, the relative molecular mass × 100 = 12 × 6150 × 100 =48.

So the answer is:

(1) four; 9:1:4; (2) 48