Ocean water contains 3.5 nacl by mass. what mass of ocean water in grams contains 45.8 g of nacl

Mass percentage of sodium chloride(NaCl) in ocean waters = 3.5 %

That means 3.5 g sodium chloride(NaCl) is present for every 100 g of ocean water.

The given mass of sodium chloride(NaCl) is 45.8 g

Calculating the mass of ocean waters that would contain 45.8 g sodium chloride(NaCl):

                     = 1309 g ocean water

Therefore, 45.8 g sodium chloride is present in 1309 g ocean water.

h let me think

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.