The thermite reaction, in which powdered aluminum reacts with iron oxide, is highly exothermic: 2al(s) + fe2o3(s)→al2o3(s) + 2fe(s) use standard enthalpies of formation to find δh∘rxn for the thermite reaction. express the heat of the reaction in kilojoules to four significant figures.

Which of the following contributes to the structural rigidity of cellulose? adjacent glucose polymers are stabilized by hydrogen bonding. glucose residues are joined by (α1→4) linkages. cellulose is a highly branched molecule. the conformation of the glucose polymer is a coiled structure.

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.

How is the way a mixture is combined different from how a compound is combined?