Classify as a strong, weak, or non electrolyte. FeCl2, HBr, HCN, CaCO3.

I put FeCl2 and HBr as strong, HCN as weak and CaCO3 as non.

To classify substances as strong, weak, or non-electrolytes, you need to determine their ability to dissociate or ionize in water.

1. FeCl2 (Iron(II) chloride): Strong electrolyte
Iron(II) chloride is an ionic compound that dissociates completely into Fe2+ and 2Cl- ions in water. Since it dissociates fully, it is considered a strong electrolyte.

2. HBr (Hydrobromic acid): Strong electrolyte
Hydrobromic acid is a strong acid that dissociates completely into H+ and Br- ions in water. Similar to ionic compounds, strong acids also dissociate fully, making HBr a strong electrolyte.

3. HCN (Hydrogen cyanide): Weak electrolyte
Hydrogen cyanide is a weak acid that only partially dissociates into H+ and CN- (cyanide) ions in water. Since it only dissociates partially, it is categorized as a weak electrolyte.

4. CaCO3 (Calcium carbonate): Non-electrolyte
Calcium carbonate is an ionic compound, but its solubility in water is limited. It does not dissociate into ions significantly, therefore it is considered a non-electrolyte.

So, your classification is correct:
- FeCl2 and HBr are strong electrolytes.
- HCN is a weak electrolyte.
- CaCO3 is a non-electrolyte.