In the question stem, we are told that equal molar amounts of  and glucose are added to containers  and , respectively. The change in boiling point of water is a colligative property that is dependent on the number of dissolved solute particles, regardless of their identity. The addition of 5 moles of  will result in approximately 10 moles of dissolved solute, since each mol of  can dissociate into two ions, according to the following reaction:

Glucose, on the other hand, does not dissociate and simply remains as intact molecules. Thus, the addition of 5 moles of glucose to container  results in 5 moles of dissolved solute. Since solution  contains approximately twice as many dissolved solute particles as does solution , it will experience a greater increase in the boiling point of water.

We are given the concentration of  in solution and asked to find the pH. To do this, we must make use of the following equation:

It is also important to realize that  is a strong base and will thus dissociate completey according to the following reaction:

Thus, for every one mol of  that reacts, an equal number of moles of  will be produced. And since there are   to begin with, then   will be produced.

Remember that this calculated value so far is the pOH, not the pH! To calculate the pH, it is vital to remember that  at . Thus,

For a solution of known volume and concentration (molarity in this case), the volume needed to dilute the solution to a desired concentration may be found using the formula:

Where  and  are the initial and final concentrations, and  and  are the initial and final volumes. So, for 750mL (0.750L) of a 0.050M solution diluted to 0.015M:

Solving for :

Now that we know the total volume needed, we may find the volume that must be added by subtracting the initial volume () from the final volume ():

1.75L of water must be added to 750mL of 0.050M  in order to achieve a final concentration of 0.015M

Since  is a strong acid, calculations should be carried out assuming that the compound dissociates completely:

 and  are produced in a 1:1 ratio to total dissolved , so the concentration of  in solution is the same as the concentration of :

pH is related to the concentration of :

Osmotic pressure is represented by:

Where  Van’t hoff factor, ,  gas constant ,  temperature in . The Van’t hoff factor is a unitless number that represents the amount of ionic species that the compound  will dissociate in solution.  is part of a large group of molecules classified as hydrocarbons which normally do not dissociate at all in solution. Therefore, .

Plug in known values and solve.

In order to calculate the concentration, we must use molarity formula:

We must use the molecular weight of  to calculate the moles of solute:

In order to calculate the concentration, we must use molarity formula:

We must use the molecular weight of  to calculate the moles of solute:

In order to calculate the number of milliliters, we must first determine the number of moles in 5 grams of  using its molecular weight as a conversion factor:

Using the concentration units as a conversion factor and the number of moles calculated, the number of milliliters can be calculated:

Use the dilution formula:

Rearranging this equation gives:

Plugging in the values gives:

Therefore, after diluting the solution to 20mL, the solution concentration would be lowered from 0.50M to 0.25M.

Solutes that dissociate completely in a solution are called strong electrolytes. Weak electrolytes stay paired to some extent in solutions. As a result, strong electrolytes include ionic compounds and strong acid and bases.