Question

Lithium and nitrogen react in a combination reaction to produce lithium nitride:

6Li (s) + N2 (g) → 2Li3N (s)

In a particular experiment, 4.50-g samples of each reagent are reacted. The theoretical yield of lithium nitride is ________ g.

Lithium and nitrogen react in a combination reaction to produce lithium nitride:

6Li (s) + N2 (g) 2Li3N (s)

In a particular experiment, 4.50-g samples of each reagent are reacted. The theoretical yield of lithium nitride is ________ g.

A. 3.76
B. 22.6
C. 4.53
D. 7.52
E. 11.2

Answer 1

The theoretical yield of lithium nitride is 7.52 g.

Step-by-step explanation:

`6Li (s) + N_2 (g)\rightarrow 2Li_3N (s)`

Moles of lithium =
`(4.50 g)/(7 g/mol)=0.6428 mol`

Moles of nitrogen gas =
`(4.50 g)/(28 /mol)=0.1607 mol`

According to reaction, 6 moles of lithium reacts with 1 mole of nitrogen gas.

Then 0.6428 moles of lithium will react with:

`(1)/(6)* 0.6428=0.10714 mol` of nitrogen gas

As we can see that moles of lithium are in limiting amount. So, the moles of lithium nitride will be depend upon the moles of lithium. Hence, lithium is a limiting reagent.

According to reaction,6 moles of lithium gives 2 moles of lithium nitride.

Then 0.6428 moles of lithium will give:

`(2)/(6)* 0.6428 mol=0.21428 mol` of lithium nitride

Mass of 0.21428 moles of lithium nitride:

0.2143 mol × 35 g/mol= 7.52 g