When an ionic compound such as sodium chloride (NaCl) is placed in water, the component atoms of the NaCl crystal dissociate into individual sodium ions (Na+) and chloride ions (Cl-). In contrast, the atoms of covalently bonded molecules (e.g., glucose, sucrose, glycerol) do not generally dissociate when placed in aqueous solution. Which of the following solutions would be expected to contain the greatest number of solute particles (molecules or ions)?

Question

Quizplus · Accepted Answer

The solution with the greatest number of solute particles will be the one with the highest molarity (M). Molarity is defined as the number of moles of solute per liter of solution. Thus, a 1.0 M NaCl solution (choice C) will have more solute particles than a 0.5 M NaCl solution (choice A) or a 0.5 M glucose solution (choice B). A 1.0 M glucose solution (choice D) will have the same number of solute particles as the 0.5 M glucose solution (choice B), as the number of particles does not change with the concentration of a covalently bonded molecule. Finally, the volume of the solution (2 L vs 1 L) does not affect the number of solute particles, so choice E can be eliminated.

When an Ionic Compound Such as Sodium Chloride (NaCl) Is