How many moles of a gas mixture would be needed to provide 0.775 mole O2, if the mole fraction of O2 in the mixture is 0.440?

13. a covalent bond between two atoms is likely to be polar if: a. one of the atoms is much more electronegative than the other. b. the two atoms are equally electronegative. c. the two atoms are of the same element. d. the bond is part of a tetrahedrally shaped molecule. e. one atom is an anion.