Question

5 which of the following choices describes an investigation in which a student is studying the effect of increasing the surface area of a solute? a a student mixes sodium chloride in various volumes of water and calculates the concentration of each solution. b a student drops a sugar cube in water and mixes a tablespoon of loose sugar in a second container of water to see which one dissolves more quickly. c a student pours a single container of salt water on the lab counter and measures how long it takes to evaporate. d a student mixes a teaspoon of copper sulfate into each of two identical beakers of water and stirs them at different speeds to see which one dissolves more quickly.

Explanation:

• Option A: Focuses on volume of water and concentration, not surface area of solute.
• Option B: Compares a sugar cube (small surface area) and loose sugar (larger surface area) dissolving in water. This is about the effect of surface area of the solute (sugar).
• Option C: Deals with evaporation of salt - water solution, not related to surface area of solute affecting dissolution.
• Option D: Focuses on stirring speed (agitation) affecting dissolution, not surface area of solute.

Answer:

B. A student drops a sugar cube in water and mixes a tablespoon of loose sugar in a second container of water to see which one dissolves more quickly.