Question

Lithium and nitrogen react in a combination reaction to produce lithium nitride:. 6Li(s)+N2(g)→2Li3N(s). In a particular experiment, 5.00-g samples of each reagent are reacted. The theoretical yield of lithium nitride is __________ g.

Answer 1

We are given with the reaction that produces lithium nitride from the rection of lithium and nitrogen. This is expressed in the balanced equation: 6Li + N2= 2 Li3N. We convert the given mass to moles and multiply by stoich. ratio of 2/6 or 1/3, then multiply by the mass of lithium. The theoretical yield thus is 8.33 grams lithium nitride.

Answer 2

Answer:

8.33 g of Lithium Nitride

Explanation:

Well, the answer provided by the Brainly user is correct. The problem is that he didn´t explain why he/she did the math using one reactant instead of the other.

When you have more than a reactant with a fixed mass in your experiment, you must consider which is the limiting reactant!

Please, see the picture for deeper details.

All in all, you have 5g of Li and 5g of N2. For 41.4 g of Li you need 28 g of N2, therefore for 5g of Li you´d need 3.38 g of N2 (PLEASE SEE THE PICTURE! Otherwise, it is not easy to see).

Therefore, for 5 g of Li you need 3.38 g of N2 whereas you infact have 5 g! See? There are 1.62 g of N2 that are not taking part in the reaction! So, the N2 is the reactant in excess reagent!!!

All this is correct only if we consider that the reaction has a 100% yield. The exercise does not mention anything about it, so I´ll consider it like this.