Question

From the following list of elements, check those will always form ionic compounds in a 3:1 ratio with nitrogen.
Choose one or more:
A. sulfur
B. krypton
C. selenium
D. bromine
E. lithium
F. strontium
G. potassium
H. zinc
I. copper

Answer 1

Given info : from the following list of elements, check those will always form ionic compound in a 3 : 1 ratio with nitrogen.

A. sulfur

B. krypton

C. selenium

D. bromine

E. lithium

F. strontium

G. potassium

H. zinc

I. copper

Solution : let Element is X forms a compound with N is X₃N (as ratio 3 : 1 ). It is nitride. I.e., N³¯ so element must have +1 charge to form this compound.

Sulfur => sulphur form (SN)x , S₄N etc.. but never forms S₃N.

Krypton is chemically inert element. So it can't be.

Configuration of Selenium = [Ar]3d¹⁰4s²4p⁴ , so it can lose one electron and form Se⁺ ion therefore it can form Se₃N.

Bromine is halogen so it can't form.

Lithium ion is Li⁺ so yes it can form Li₃N.

Strontium => [kr]4s² so can't form.

Potassium => K⁺ ion so it can form.

Zinc => [Ar]3d¹⁰ 4s², hard to remove an electron so it can't form.

Copper, Cu exist in Cu⁺ form so it can form Cu₃N.

Therefore copper, potassium, lithium, selenium form a compound with nitrogen in a ratio of 3 : 1.