Name the reagents used in the following reactions:
$(i)$ Oxidation of a primary alcohol to carboxylic acid.
$(ii)$ Oxidation of a primary alcohol to aldehyde.
$(iii)$ Bromination of phenol to $2,4,6-$tribromophenol.
$(iv)$ Benzyl alcohol to benzoic acid.
$(v)$ Dehydration of propan$-2-$ol to propene.
$(vi)$ Butan$-2-$one to butan$-2-$ol.

(N/A) $(i)$ Acidified potassium permanganate $(KMnO_4/H^+)$ or acidified potassium dichromate $(K_2Cr_2O_7/H^+)$.
$(ii)$ Pyridinium chlorochromate $(PCC)$ in dichloromethane $(CH_2Cl_2)$.
$(iii)$ Bromine water $(Br_2/H_2O)$.
$(iv)$ Acidified potassium permanganate $(KMnO_4/H^+)$.
$(v)$ Concentrated phosphoric acid $(H_3PO_4)$ or concentrated sulfuric acid $(H_2SO_4)$ at $440 \ K$.
$(vi)$ Sodium borohydride $(NaBH_4)$ or Lithium aluminium hydride $(LiAlH_4)$.