4Al (s) + 3O2 (g) --> 2Al2O3 (s) If 31.7 g Al and 25.5 g O2 are available, which one is the limiting reactant when forming aluminum oxide?
Give the chemical formula for the limiting reactant only. No numbers or physical states!

In the analysis of hair and fiber samples, which does a compound comparison microscope allow for that a conventional compound microscope does not? a. simultaneous observation b. polarization c. fluorescence d. higher magnification

Voltaic cells produce a positive overall charge. what does this indicate? a. the reaction is likely to be endothermic. b. the reaction is spontaneous. c. the reaction is not likely to occur. d. the reaction is not spontaneous.

The ammonia molecule in the diagram has the observed bond orientation because