In the fc alkylation of 1,4 dimethoxybenzene using t-butanol in the presence of concentrated sulfuric acid, what was the function of sulfuric acid?
it turn t-butanol to a stable tertiary carbocation, t-butyl cation, which served as the electrophilic aromatic substitution reaction, namely fc alkylation in this case
it activated 1,4 dimethoxybenzene so that fc reaction could go more smoothly
it can be transformed into alcl3 to catalyze the said fc alkylation
when it was added to the reaction mixture, the mixtures temperature went up, which made the reaction go faster