What is the pH of a solution prepared by dissolving 1.533 g HCl in water to make 420 mL of solution
mols HCl = grams/molar mass.
(HCl) = M = mols/L soln.
pH = -log(HCl)
To find the pH of a solution, you need to know the concentration of the hydrogen ions (H+). In this case, we can start by calculating the concentration of HCl in the solution.
Step 1: Calculate the molarity of HCl
Molarity (M) is defined as the number of moles of solute per liter of solution. We can use the formula:
M = (moles of solute) / (volume of solution in liters)
First, we need to convert the mass of HCl into moles. The molar mass of HCl is 36.46 g/mol (1.007 g/mol for hydrogen + 35.45 g/mol for chlorine).
moles of HCl = (mass of HCl) / (molar mass of HCl)
= 1.533 g / 36.46 g/mol
Step 2: Calculate the molarity
Next, we'll calculate the molarity using the volume provided in the question.
Molarity (M) = (moles of HCl) / (volume of solution in liters)
= (1.533 g / 36.46 g/mol) / (420 mL / 1000 mL/L)
= (0.042 mol) / (0.42 L)
= 0.1 M
Now that we have the molarity of HCl in the solution, we can find the concentration of H+ ions. Since HCl is a strong acid and completely ionizes in water, the concentration of H+ ions is the same as the molarity of HCl.
[ H+ ] = 0.1 M
Finally, we can calculate the pH of the solution using the formula:
pH = -log [ H+ ]
pH = -log (0.1)
pH = -(-1)
pH = 1
Therefore, the pH of the solution prepared by dissolving 1.533 g HCl in water to make 420 mL of solution is 1.