Question

A white anhydrous powder that dissolves in water to

form a blue aqueous solution could be
A) CuSO₄
B) CaSO₄
C) BaSO₄
D) MgSO₄

Answer 1

The white anhydrous powder that dissolves in water to form a blue aqueous solution is CuSO₄. When CuSO₄ dissolves in water, it forms hydrated Cu²+ ions in the form of pale blue [Cu(H₂O)]²+. So the correct answer is Option A.

Step-by-step explanation:

The white anhydrous powder that dissolves in water to form a blue aqueous solution is A) CuSO₄. When CuSO₄ dissolves in water, it forms hydrated Cu²+ ions in the form of pale blue [Cu(H₂O)]²+. The addition of aqueous ammonia to the solution results in the formation of intensely blue-violet [Cu(NH₃)4(H₂O)2]²+ ions, usually written as [Cu(NH₃)4]²+ ion, because ammonia replaces water molecules from the hydrated Cu²+ ion.