Science ·Class 9 Science

Copper sulfate conducts electricity in the molten state but not in the solid state. Class 9

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· Jul 06, 2026 · Reviewed & updated Sep 17, 2026 · 1 min read

Copper sulfate conducts electricity in the molten state but not in the solid state. Class 9

Question 1.

Assertion (A): Copper sulfate conducts electricity in the molten state but not in the solid state. Class 9

Reason (R): Copper and sulfate ions are fixed in the lattice in molten state, while in solid state they can move freely.

Choose the correct option:

(i) Both A and R are true, and R is the correct explanation of A.

(ii) Both A and R are true, but R is not the correct explanation of A.

(iii) A is true, but R is false.

(iv) A is false, but R is true.

Answer:

(iii) A is true, but R is false. Assertion A is TRUE: Copper sulfate (an ionic compound) conducts electricity in the molten state but not in the solid state.

Reason R is FALSE: The reason stated in R is the opposite of what actually happens. In the solid state, copper and sulfate ions are fixed in the lattice (they cannot move freely), which is why the solid does not conduct electricity. In the molten state, the ions are free to move, which is why the molten state conducts electricity. The reason has incorrectly swapped the conditions for the solid and molten states.