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Assertion (A): Copper sulfate conducts electricity in the molten state but not in the solid state. 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.
View Answer
Answer: (iii)
- A is true — molten copper sulfate conducts, solid does not.
- R is false — it is the other way round: ions are fixed in the solid and free to move in the molten state.
Option
Verdict & why
(i)
Both A and R are true, and R is the correct explanation of A.
Wrong
— R is
false
, so it cannot explain A.
(ii)
Both A and R are true, but R is not the correct explanation of A.
Wrong
— R is not true.
(iii)
A is true, but R is false.
Correct answer
— A is true; R reverses the facts. Ions are fixed in the
solid
lattice and free to move when
molten
.
(iv)
A is false, but R is true.
Wrong
— A is true and R is false.
