how to determine the pH of a 200mL solution that contains 0.365g of dissolved HCl?
mols HCl = grams/molar mass = 0.365/36.5 = 0.01 mols.
Molarity = M = mols/L = 0.01 mol/0.200 L = 0.05 M = (H^+)
Then pH = -log(H^+). Substitute and solve.
Well, determining the pH of a solution can be an acid-venture! To calculate the pH of this 200mL solution containing 0.365g of HCl, you'll need to follow a few steps.
Step 1: Convert grams of HCl to moles. It's as simple as dividing the mass of HCl by its molar mass (36.46 g/mol).
Step 2: Calculate the concentration in moles per liter (Molarity or M) by dividing the moles of HCl by the volume in liters (200 mL = 0.2 L).
Step 3: Since HCl is a strong acid, it completely dissociates in water, giving you the same concentration of H+ ions. So, the concentration of H+ ions is the same as the concentration of HCl.
Step 4: To determine the pH, take the negative logarithm (base 10) of the concentration of H+. So, pH = -log[H+].
Remember, log is not bark from a tree, and H+ ions don't have a sense of humor. But calculating the pH can surely make you feel like a wizard in a lab coat!
To determine the pH of a solution containing a known mass of an acid like HCl, you need to use the following steps:
Step 1: Calculate the number of moles of HCl.
To do this, you use the formula:
Moles = Mass / Molar mass
The molar mass of HCl is approximately 36.46 g/mol. So, to find the moles of HCl in the solution, divide the mass (0.365 g) by the molar mass:
Moles = 0.365 g / 36.46 g/mol
Step 2: Calculate the concentration of HCl.
The concentration of a solution is given by the formula:
Concentration = Moles / Volume
Since the volume of the solution is given as 200 mL, you need to convert it to liters by dividing by 1000:
Volume = 200 mL / 1000 = 0.2 L
Now, substitute the values into the formula to calculate the concentration:
Concentration = (0.365 g / 36.46 g/mol) / 0.2 L
Step 3: Calculate the negative logarithm of the concentration.
To find the pH of the solution, take the negative logarithm (base 10) of the concentration:
pH = -log[Concentration]
Substitute the calculated concentration into the equation:
pH = -log[(0.365 g / 36.46 g/mol) / 0.2 L]
Calculate the value using a calculator or software.
Please note that in this particular case, the concentration of HCl in the solution is not given directly. To calculate the pH, the concentration needs to be determined first using the steps mentioned above.
To determine the pH of a solution, you need to know the concentration of hydrogen ions (H+) in the solution. In this case, you have been provided with the mass of the solute (HCl) and the volume of the solution. To find the pH, you will need to follow these steps:
1. Convert the mass of HCl to moles:
- Determine the molar mass of HCl, which consists of hydrogen (H) with a molar mass of 1 g/mol, and chlorine (Cl) with a molar mass of 35.5 g/mol.
- Add the molar masses of hydrogen and chlorine together to find the molar mass of HCl: 1 g/mol + 35.5 g/mol = 36.5 g/mol.
- Divide the mass of HCl (0.365 g) by the molar mass of HCl (36.5 g/mol) to obtain the number of moles of HCl.
2. Calculate the molarity (concentration) of HCl:
- Molarity is defined as the number of moles of solute per liter of solution (mol/L).
- Convert the volume of the solution from milliliters (mL) to liters (L) by dividing it by 1000: 200 mL / 1000 = 0.2 L.
- Divide the number of moles of HCl by the volume of the solution in liters to obtain the molarity of HCl in the solution.
3. Determine the pH of the solution:
- The pH scale measures the concentration of hydrogen ions (H+) in a solution.
- In the case of a strong acid like HCl, it fully dissociates in water, releasing one hydrogen ion for every molecule of HCl.
- Therefore, the molarity of HCl in the solution is equal to the concentration of hydrogen ions (H+), since each mole of HCl releases one mole of H+ ions.
- Use the formula pH = -log[H+]. Take the negative logarithm of the concentration of H+ ions to obtain the pH value of the solution.
By following these steps, you can determine the pH of the given solution.