Based on periodic trends of electronegativity, what statement regarding the halogens is most accurate? a) flourine has the lowest electronegativity. b) iodine has the strongest tendency to attract electrons. c) fluorine has the strongest tendency to attract electrons. d) because of it's low electronegativity, iodine does not readily form compounds.

If I remember correctly the answer would be C.  Electronegativity increases going right from the Alkali Metals to the Noble Gasses with the gasses being the strongest.  Also going up from Ununoctium up to Helium.

n2(g) + 3h2-> 2nh3(g)   this is the balanced equation

note the mole ratio between n2, h2 and nh3.   it is 1 : 3 : 2   this will be important.

moles n2 present = 28.0 g n2 x 1 mole n2/28 g = 1 mole n2 present

moles h2 present = 25.0 g h2 x 1 mole h2/2 g = 12.5 moles h2 present

based on mole ratio, n2 is limiting in this situation because there is more than enough h2 but not enough n2.

moles nh3 that can be produced = 1 mole n2 x 2 moles nh3/mole n2 = 2 moles nh3 can be produced

grams of nh3 that can be produced = 2 moles nh3 x 17 g/mole = 34 grams of nh3 can be produced

note:   the key to this problem is recognizing that n2 is limiting, and therefore limits how much nh3 can be produced.

your answer would be a. 12.5 kg