Aballoon contains 0.76 mol n2, 0.18 mol o2, 0.031 mol he and 0.026 mol h2 at 749 mm hg. what is the partial pressure (in mm hg) of o2? give a numeric answer only, no units.

Consider the following system at equilibrium. caco3(s) ca2+(aq) + co32–(aq) the addition of which compound will cause a shift in equilibrium because of a common ion effect? ccl4 co2 cuso4 na2co3

Significant figures are digits read directly from the measuring instrument plus one more digit, which is __ by the observer.

Why is the bond angle in a water molecule less than the bond angle of methane? a. the central oxygen atom in water has two lone pairs of electrons, whereas the central carbon atom in methane has no lone pairs. b. the central hydrogen atom in water has one lone pair of electrons, whereas the central carbon atom in methane has two lone pairs. c. the central oxygen atom in water has four lone pairs of electrons, whereas the central carbon atom in methane has only one lone pair. d. the central oxygen atom exerts more repulsive force on surrounding atoms than the central carbon atom in methane does. reset next