Question

An element X, forms a compound with Nitrogen for which the formula is X3N. If 40.21% of the compound is Nitrogen, what is the atomic weight of X?

Answer 1

Answer:

6.94 (Li) and the compound is, Li3N (Lithium Nitride)

Explanation:

lets get started,

40.21% of the compound is nitrogen

so, we need to find the molecular weight of the compound.

mass percentage = molecular weight of nitrogen / molecular weight of compound * 100

molecular weight of compound is say "y"

molecular weight of nitrogen is 14g/mol

so,

14/y = 40.21%

y= 14/0.4021

y = 34.817

so, total molecular weight of compound is = 34.817

we know that, Nitrogen molecular weight is 14, so

molecular weight of X3 = 34.817 - 14

= 20.817

there are 3 X atoms, hence, divide it by 3

20.817/3

= 6.94

Hence X molecular weight is = 6.94

which is molecular weight of Lithium (Li)