When a zinc rod is dipped in copper sulfate solution, the following changes occur:
- Zinc rod slowly loses its weight: This is correct because zinc displaces copper from copper sulfate, resulting in the loss of zinc's mass.
- Copper settles at the bottom of the beaker: This is also correct as elemental copper is produced and can settle at the bottom.
- Blue color of copper sulfate disappears: This is correct because as copper ions are displaced by zinc, the blue color associated with copper sulfate fades.
Based on this analysis, the correct answer is:
(B) (i), (ii), and (iii).