It’s not steam, but in a namesake process, oil refineries use these substances (-5[1])to “crack” high-molecular weight petroleum into gasoline products. These substances are (10[1])“perfect” if their efficiency is limited only by diffusion. (10[2])The efficiency of these substances is impeded in “poisoning.” (10[3])Leaded (10[2])gasoline (-5[1])can impede (10[2])the removal of carbon dioxide (10[1])from exhaust with a “converter” (10[1])named for these (10[1])substances. (10[2])These substances, which are called heterogeneous if they are in a different phase (10[1])than reactants, provide a pathway with lower activation energy. (10[1])For 10 points, name these species that increase the rate of a reaction without being consumed. ■END■