The dichromate ion, Cr2O72-, is formed from the chromate ion, CrO42, on addition of (A) acid. (B) base. (C) an oxidizing agent. (D) a reducing agent. (E) none of these, 2 Which is not a Lewis acid? (A) NF3 (B) Al2Br6 (C) BF3 (D) CdCl2 (E) LaCl3 3 In the acid-base reaction 2HSO3F+SbF5H2SO3F++F5SbOSO2F (A) SbF5 serves as a Brsnsted-Lowry acid. (B) SbFs serves as a solvent-system base. (C) HSO3F serves as a Lewis acid. (D) SbF5 serves as a Lewis acid. (E) HSO3F serves as a solvent-system base. 4 The strongest acid that can exist in liquid acetic acid, (A) OH (B) CH3CO2 (C) CH3CO2H (D) CH3CO2H2+ (E) H3O+ Which is not isoelectronic with B5H52 ? (A) C2B3H5 (B) B5H6 (C) B5H7 (D) SB4H4 (E) NB4H4 Given these standard reduction potentials in acid solution: Fe3++cFe2+Fe2++2eFeE=0.77VE=0.47V The standard reduction potential for in acid solution is (A) 1.24V Fe3++3eFe (D) 0.06V (B) 0.30V (C) 0.06V (E) 0.10V