Question

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 particles (molecules or ions)? A) 1 L of 0.5 M NaCl B) 1 L of 0.5 M glucose C) 1 L of 1.0 M NaCl D) 1 L of 1.0 M glucose E) C and D will contain equal numbers of particles.

Answer 1

Answer:

Solution (C) contains greatest number of particles.

Explanation:

Molarity of a solution = (no. of moles of solute in solution)/(volume of solution in liter). Here, NaCl and glucose are solutes.

1 mol = $6.023\times 10^{23}$ number of molecules/ions

Glucose is a non-electrolyte and NaCl is an electrolyte

So, 1 mol glucose = $6.023\times 10^{23}$ number of molecules of glucose

     1 mol NaCl = $1.205\times 10^{24}$ number of ions

Solution    moles of solute (molarity$\times$volume)       no. of  particles

   A                       0.5                                                              $6.023\times 10^{23}$

   B                        0.5                                                             $3.012\times 10^{23}$

   C                        1.0                                                              $1.205\times 10^{24}$

   D                        1.0                                                              $6.023\times 10^{23}$

So, solution (C) contains greatest number of particles