Question

write the empirical formula of at least four binary ionic compounds that could be formed from the following ions: fe²⁺, au³⁺, i⁻, s²⁻

Explanation:

Step1: Combine Fe²⁺ and I⁻

The charges must balance. Fe²⁺ has a +2 charge and I⁻ has a -1 charge. So we need 2 I⁻ for each Fe²⁺. The formula is FeI₂.

Step2: Combine Fe²⁺ and S²⁻

The +2 charge of Fe²⁺ and -2 charge of S²⁻ balance each other in a 1:1 ratio. The formula is FeS.

Step3: Combine Au³⁺ and I⁻

Au³⁺ has a +3 charge and I⁻ has a -1 charge. We need 3 I⁻ for each Au³⁺. The formula is AuI₃.

Step4: Combine Au³⁺ and S²⁻

To balance the +3 charge of Au³⁺ and -2 charge of S²⁻, we find the least - common - multiple of 3 and 2 which is 6. So we need 2 Au³⁺ and 3 S²⁻. The formula is Au₂S₃.

Answer:

FeI₂, FeS, AuI₃, Au₂S₃