Question:
Write the formulae of the compounds formed from the following pairs of ions.
(A) Ca²⁺ and Br⁻
(B) Al³⁺ and CO₃²⁻
(C) K⁺ and SO₄²⁻
(D) NH₄⁺ and Cl⁻
Answer:
Verified
To write the formulae of the compounds use the criss-cross method to balance the positive and negative charges.
| Pair of Ions | Formula Formed | Name |
|---|---|---|
| (A) Ca²⁺ and Br⁻ | CaBr₂ | Calcium bromide |
| (B) Al³⁺ and CO₃²⁻ | Al₂(CO₃)₃ | Aluminium carbonate |
| (C) K⁺ and SO₄²⁻ | K₂SO₄ | Potassium sulphate |
| (D) NH₄⁺ and Cl⁻ | NH₄Cl | Ammonium chloride |
