first off you wrote down the equation wrong its Co(OH)3 and its pronounced cobalt three hydroxide additionally from looking at the formula you know that cobalt has a +3 charge
H+ and OH- could be considered the spectator ions in that reaction, although you don't typically count them, because that's just water. Really, this reaction can be summed up by saying: 2Co+3(aq) + 3SO4-2(aq) --> Co2(SO4)3(s). The precipitate is cobalt(III) sulfate.
If by 'acid group' you mean a carboxyl group (COOH), and by 'methyl group' you mean the carbon is right at the end, then it isn't really a methyl group, just a normal carboxylic acid2 carbons: Ethanoic Acid, CH3COOH3 carbons: Propanoic Acid, CH3CH2COOHIf the methyl group was in the middle. The number of carbons here includes the methyl group, but note the name of the chemical doesn't correspond to the total number, but by the longest chain possible.4 carbons: 2-Methylpropanoic Acid, CH3CH(CH3)COOH5 carbons: 2-Methylbutanoic Acid, CH3CH2CH(CH3)COOH3-Methylbutanoic Acid, CH3CH(CH3)CH2COOH