Answer and explanation
we are given the reaction between lithium and nitrogen in the formation of lithium nitride .
firstly we balance the reaction
6Li + N₂ => 2Li₃N
now that we have balanced the reaction we then proceed to calculate the mass of nitrogen that reacted when 500 grams of lithium nitride is formed.
to do this we first need to determine the moles of lithium nitride in 500 grams of lithium nitride
moles = mass (g) / molar mass (g/mol)
= 500g / 34.83g/mol
= 14.36 mols
now we know that 14.36 moles of lithium nitride formed.
from the balanced chemical reaction, we know that 1 mole of nitrogen reacts to form 2 moles of lithium nitride
therefore the moles of nitrogen that reacted must be
1/2 x 14.36 = 7.18 moles
now we know that 7.18 moles of nitrogen reacted.
to find the mass, we simply use the following equation
mass = n x M
where n is moles
M is Molar mass
mass = 7.18 moles x 14.00g/mol
= 100.49 grams
100.49 grams of nitrogen reacted in the reaction