Chemistry related

Question

The electrical conductance of a solution of Ba(OH)2 slowly decreases upon the addition of HSO4 to a minimum, and then slowly increases. The best experimental evidence for this is

(A)The Ba(OH) solution becomes more dilute since its volume is increased by adding the H2SO4solution.

(B)Ions are removed from the solution by the formation of water and insoluble BaSO4.

(C)The inter-ionic attraction effect is increased by adding the H2SO4

(DAn electric lamp placed in a circuit in series with the solution becomes dim as the H2SO4 is added and then becomes bright again.

(E) An indicator placed in the solution changes color.

could you explain why and how you got that answer?

Answer 1

The key part of this question is that it wants you to explain how you would be able to tell that the conductivity drops and then rises again. Because many of those answers are true things happening in the container as the acid is added.

Conductivity is the solution's ability to pass electricity through it, so to detect that we would need to observe the flow of electricity changing. The only answer that does that is D. As conductivity drops, less current flows through the circuit and the lamp dims. Then when conductivity rises again (after all the BaSO4 has formed), more current can flow and the lamp brightens.