Question

Sodium (Na) reacts with nitrogen gas (N2) to produce sodium nitride. If a student collects 2.5 moles of sodium nitride (NaN3) after the reaction has been completed, determine the number of moles of nitrogen that were initially present.

2Na + 3N2 -> 2NaN3

Your answer:

3.75 mole N2


1.2 mole N2


3.87 mole N2

Answer 1

Answer : The correct option is, 3.75 mole
`N_2`

Explanation : Given,

Moles of
`NaN_3` = 2.5 mol

The balanced chemical equation is:

`2Na+3N_2\rightarrow 2NaN_3`

From the balanced reaction we conclude that

As, 2 moles of
`NaN_3` produce from 3 moles of
`N_2`

So, 2.5 moles of
`NaN_3` produce from
`(3)/(2)* 2.5=3.75` moles of
`N_2`

Therefore, the moles of
`N_2` initially present was, 3.75 moles.