The equation shows lithium reacting with nitrogen to produce lithium nitride. 6 Li plus cap n sub 2 ce bond right arrow 2 Li sub 3 cap n If 12 mol of lithium were reacted with excess nitrogen gas, how many moles of lithium nitride would be produced?

The balanced equation shows that 6 mol of lithium produce 2 mol of lithium nitride. Since 12 mol of lithium is twice 6 mol, it produces twice 2 mol, or 4.0 mol of lithium nitride. The correct choice is A, 4.0 mol.

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