Question

9 Which of the following formula for ionic compounds is the least likely to be correct? A. CaCl2 B. Cr203 C. NaSO4 D. MgO E. NHACI

Answer 1

sol:-

to find the least ionic compound we must see following rule:-

• small size of cation
• large size of anion
• charge must be large in compound

A):- CaCl₂ = Ca²⁺ + Cl^-

B):- Cr₂O₃ = Cr³⁺ + O^2-

C):- NaSO₄ = Na⁺ + SO₄^-

D):- MgO = Mg²⁺ + O^2-

E):- NH₄Cl = NH₄⁺ + Cl^-

from the above ionic compound Cr₂O₃ have difference in size of anion and cation and have also larger charge

so, Cr₂O₃ is least ionic compound.