A better reagent to oxidise primary alcohols into aldehyde is

Y in the above reaction is

An organic compound with molecular formula $$\mathrm{C}_7 \mathrm{H}_8 \mathrm{O}$$ dissolves in $$\mathrm{NaOH}$$ and gives a characteristic colour with $$\mathrm{FeCl}_3$$. On treatment with bromine, it gives a tribromo derivative $$\mathrm{C}_7 \mathrm{H}_5 \mathrm{OBr}_3$$. The compound is

In Kolbe's reaction the reacting substances are