25. Which line-angle formula corresponds to the chair conformation shown below? Br H3CH2C CH2CH3 Br (A) CH2CH3 Br (B) CH2CH3 Br (C) CH2CH3 Br (D)

5. The following two reactions are important in the blast furnace production of iron metal from iron ore (Fe2O3): Using these balanced reactions, how many moles of O2 are required for the production of 2.51 kg of Fe? (Molecular weight of Fe = 55.85 g/mol) (A)33.7 moles (B) 15.0 moles (C) 135 moles (D)44.9 moles (E) 1.88 moles