A research team needs to separate sodium chloride from of a aqueous solution while…
CHEMISTRY · Multi-part · AP · Chemistry · Properties of Substances and Mixtures · Properties of Substances and Mixtures
Problem
A research team needs to separate sodium chloride from 1.00L of a 0.010mol L−1 aqueous solution while recovering the water for later use.
Their initial idea is to push the solution through a standard 0.45μm membrane filter commonly used for sterilizing growth media.
(a) Using appropriate nanoscale reasoning, explain why the membrane filter will neither retain the hydrated Na+ and Cl− ions nor significantly alter the salt concentration of the filtrate.
(b) Design an alternative laboratory-scale procedure that would achieve the desired separation. Your design must include:
• The name of the technique
• A labeled list of the essential pieces of apparatus
• A concise, step-by-step operational outline
• Identification of the physical property that the technique exploits
(c) Describe two distinct sources of experimental error or loss that could reduce the overall efficiency of your proposed procedure, and propose a strategy to minimize each one.
(d) The team must document that their method does not chemically alter either the water or the salt. Identify one analytical test for the water and one for the recovered salt that would provide this confirmation, and briefly explain what observation would verify chemical integrity.