The balanced equation between the 
and 
is:
Formula of molarity is:
Substituting the values,
So, number of moles of is 
.
From the balanced equation it is clear that for 1 mole of , 2 moles of are required.
Hence, 0.21 mole of = 
Molar mass of = 
So, the mass of = 
(Na2Cr2O7) all the numbers are bellow not over
It would take 4 years to reach earth
the balanced equation for the formation of ammonia is
N₂ + 3H₂ ---> 2NH₃
molar ratio of N₂ to NH₃ is 1:2
mass of N₂ reacted is 8.0 g
therefore number of N₂ moles reacted is - 8.0 g / 28 g/mol = 0.286 mol
according to the molar ratio,
1 mol of N₂ will react to give 2 mol of NH₃, assuming nitrogen is the limiting reactant
therefore 0.286 mol of N₂ should give - 2 x 0.286 mol = 0.572 mol of NH₃
therefore mass of NH₃ formed is - 0.572 mol x 17 g/mol = 9.72 g
a mass of 9.72 mol of NH₃ is formed
