* Carbon tetrachloride (CCl4) is a non-polar solvent. Non-polar solvents do not readily dissolve ionic compounds, which are necessary for electrical conductivity.

* Bromide ions (Br-) are not free to move in the solution. In a non-polar solvent like CCl4, bromide ions remain tightly associated with their counterions, forming an essentially neutral, non-conducting species.

In contrast, a solution of bromide in a polar solvent like water would be conductive. Water's polarity allows it to dissolve ionic compounds, dissociating them into free ions that can carry an electrical current.

Key takeaway: Electrical conductivity in solutions depends on the presence of free, mobile ions. Non-polar solvents like CCl4 do not promote the formation of these ions, making the resulting solutions non-conductive.