If the density of solid iron is 7.87 g/cm 3 , what is the packing efficiency of Fe if it adopts a body‑centered cubic unit cell? The molar mass of Fe is 55.847 g/mol .

How does a catalyst increase the speed of a reaction? a. the catalyst eliminates the activated complex stage, allowing products to form immediately. b. the catalyst lowers the energy level of the reactants, making it easier for them to react. c. the catalyst makes it easier for the activated complex to form, lowering the activation energy. d. the catalyst raises the energy level of the products, making the reaction finish sooner. reset next