Calculate the PH and POH of an aqueous solution that is 25.00% of HCL by mass and density of 1.35g/ml

To calculate the pH and pOH of an aqueous solution, we need to determine the concentration of H+ ions or OH- ions. Since the solution contains HCl, it will dissociate completely, and the concentration of H+ ions will be equal to the concentration of HCl in the solution.

To find the concentration of HCl, we first need to determine the moles of HCl present in the solution. We can then use the molarity formula to find the concentration.

Here's the step-by-step calculation:

1) Calculate the moles of HCl:
To do this, we need to know the mass of the solution. Given that the density of the solution is 1.35 g/mL and the solution is 25.00% HCl by mass, the total mass of the solution is:
25.00g HCl / 0.25 (25.00%) = 100.00g solution

Now, we can calculate the moles of HCl:
Moles = Mass / Molar Mass
Molar mass of HCl = 1.01 g/mol (hydrogen) + 35.45 g/mol (chlorine) = 36.46 g/mol

Moles of HCl = 100.00g / 36.46 g/mol = 2.74 mol

2) Calculate the concentration of HCl:
Concentration (Molarity) = Moles / Volume (in liters)
Since we don't have the volume of the solution, we can use the density to convert the mass into volume.

Given that the density of the solution is 1.35 g/mL, the volume of the solution is:
Volume = Mass / Density = 100.00g / 1.35 g/mL = 74.07 mL

Converting the volume to liters:
Volume = 74.07 mL * (1 L / 1000 mL) = 0.07407 L

Now, we can calculate the molarity (M) of the HCl solution:
Concentration (Molarity) = 2.74 mol / 0.07407 L = 36.97 M

3) Calculate the pH and pOH:
Since HCl is a strong acid that completely dissociates in water, the concentration of H+ ions in the solution is the same as the concentration of HCl.

The pH is given by the equation:
pH = -log[H+]

The pOH is given by the equation:
pOH = -log[OH-]

Since we have HCl, which is acidic, and not OH- ions, we can calculate the pH using the concentration of H+ ions:
pH = -log[H+]
pH = -log(36.97) ≈ -1.57

To find the pOH, we can use the equation:
pOH = 14 - pH
pOH = 14 - (-1.57) = 15.57

Therefore, the pH of the solution is approximately -1.57, and the pOH is approximately 15.57.