Final answer:
NaCl is a better conductor than PCl₃ because it is a strong electrolyte that dissociates into ions, while PCl₃ does not. KBr is more conductive than CaCl₂ because its ions move at a comparable speed and it releases equal numbers of singly charged ions.
Step-by-step explanation:
1.0 M NaCl is a better conductor of electricity compared to 1.0 M PCl₃ because NaCl is a strong electrolyte that completely dissociates into Na+ and Cl− ions in solution. PCl₃, on the other hand, is a covalent compound and does not dissociate into ions when dissolved in water. The presence of free-moving ions, like Na+ and Cl−, is essential for electrical conductivity in solutions.
1.0 M KBr is more conductive than 1.0 M CaCl₂ because KBr is a 1:1 electrolyte and CaCl2 is a 2:1 electrolyte. Although CaCl₂ produces more ions (one Ca²⁺ and two Cl− per formula unit), the singly charged K+ and Br− ions move through water at a comparable speed to the doubly charged Ca²⁺, but KBr releases equal numbers of these charges, which results in KBr conducting slightly more current than CaCl₂in solution.
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