To determine which of the given compounds is an electrolyte, let's consider their properties and identify which one ionizes when dissolved in water. Electrolytes are typically strong acids, strong bases, or soluble salts.
1. BaO (Barium Oxide):
- BaO is a compound that, on contact with water, forms barium hydroxide (Ba(OH)₂), a strong base. Barium hydroxide is highly soluble and dissociates completely in water, making BaO a strong base. However, without considering its ionization in this state, as a standalone compound, it is not a common electrolyte.
2. [tex]\( Na_3PO_4 \)[/tex] (Sodium Phosphate):
- Sodium phosphate is a soluble salt. When dissolved in water, it dissociates into three sodium ions (Na⁺) and one phosphate ion ([tex]\( PO_4^{3-} \)[/tex]). Being highly soluble, sodium phosphate dissociates completely in solution, making [tex]\( Na_3PO_4 \)[/tex] a strong electrolyte.
3. [tex]\( Ag_2S \)[/tex] (Silver Sulfide):
- Silver sulfide is known to be highly insoluble in water. Due to its low solubility, it does not dissociate appreciably into ions in aqueous solution and thus is not considered an electrolyte.
4. [tex]\( Cu(OH)_2 \)[/tex] (Copper(II) Hydroxide):
- Copper(II) hydroxide is poorly soluble in water. It does not dissociate significantly into ions in aqueous solution, therefore is not considered an electrolyte.
5. [tex]\( MgCO_3 \)[/tex] (Magnesium Carbonate):
- Magnesium carbonate has limited solubility in water. It does not fully dissociate into ions when dissolved, making it a poor electrolyte.
Given the analysis above, we can see that [tex]\( Na_3PO_4 \)[/tex] (Sodium Phosphate) is the compound that behaves as a strong electrolyte due to its high solubility and ability to completely dissociate into ions in water.
Therefore, the answer is:
[tex]\[ Na_3PO_4 \][/tex]
And the correct option is at index 1 in the provided list of compounds.
