Achemist has a jar containing 388.3 g of iron filings. how many moles of iron does the
jar contain?

6.94 mol

Explanation:

Data given:

Mass of iron filings (Fe) = 388.3 g

no. of moles of iron (Fe) = ?

Solution:

For this formula will be used

       no. of moles = Mass in grams/ molar mass

molar mass of Fe = 56 g/mol

Put values in equation

                no. of moles = 388.3 g / 56 g/mol

                no. of moles = 6.94 mol

So,

no. of moles of iron in jar = 6.94 mol

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.

the correct answer is option d

explanation:

i was wrong its d because they dont use cm when calculating square roots