Lithium and Nitrogen React to Produce Lithium Nitride:
6Li(s) $\mathrm { N } _ { 2 }$

Lithium and nitrogen react to produce lithium nitride:
6Li(s) + $\mathrm { N } _ { 2 }$ (g) ? $2 \mathrm { Li } _ { 3 }$ N(s)
How many moles of $\mathrm { N } _ { 2 }$ are needed to react with 0.400 mol of lithium?

A) 2.40
B) 0.400
C) 0.133
D) 1.2
E) 0.0667