Balance the equation below and determine the mass in grams Li needed to produce 11.35g of Li3N. 6Li +N2 → 2Li3N

Answer 1

It appears you have already balanced the chemical reaction equation:

6Li + N₂ → 2Li₃N

is correct.

This balanced chemical reaction equation says that 6 moles of lithium (Li) will yield 2 moles of lithium nitride (Li₃N). The problem is that we have the amount of lithium nitride (Li₃N) given to us in grams (not moles).

Convert to moles by first getting the molar mass:

Li: 6.941 x 3 = 20.823

N:14.007 x 1 = 14.007

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Li₃N = 34.83 g/mol

(11.35 g)/(34.83 g/mol) = 0.3259 moles of Li₃N

The chemical reaction equation say there are 3 times as many moles of Li as Li₃N so there must be (0.3259 moles)(3) = 0.9776 moles of Li

Now convert 0.9776 moles of Li into grams of Li by again using the molar mass.

Li = 6.941 g/mol so (6.942 g/mol)(0.9776 moles) = 6.786 grams of Li