Question

A chemist observers that solid copper(ll) sulfate crystals do not pass through filter paper. The chemist mixes 2.5g of the blue crystals with 2L water to produce a clear, blue liquid. When filtered enough filter paper. The filtered liquid retains the same blue color. How can these observations be explained?

A. Materials pass through filter paper only when paper is wet
B. The copper sulfate crystals slide more easily through the filter paper when water is present
C. The copper sulfate reacts with water molecules to form a new substance that can pass through filter paper
D. Water acts as a solvent to break up copper sulfate into individual ions, which allows them to pass through the filter paper.

Answer 1

The observation that the solid copper(ll) sulfate crystals do not pass through the filter paper suggests that the crystals are too large to pass through the pores of the filter paper.

When the chemist mixed 2.5g of the blue crystals with 2L of water to produce a clear, blue liquid, the copper sulfate crystals dissolved in water, forming a homogeneous solution. This is consistent with the observation that the filtered liquid retained the same blue color.

Therefore, the correct explanation for these observations is that water acts as a solvent to dissolve the copper sulfate crystals into individual ions. These individual ions are small enough to pass through the filter paper, producing a clear, blue liquid that can be filtered.

Thus, the correct answer is D.