what is the pH and pOH of a soution with a volume of 5.4 that contains 15 grams of HCl and 25 grams of nitric acid
volume of 5.4 WHAT? liters?
15g HCl = how many mols? mol = g/molar mass.
25 g HNO3 = how many mols. g/molar mass = ?
Add mols H from HCl to mols H from HNO3 to find total H^+, then molarity = M = moles H^+/L solution. (L soln may be the 5.4 you wrote with no units.)
Then pH = -log(H^+) to find pH and
pH + pOH = pKw = 14 to find pOH.
Well, I must say, that solution sounds quite "acidic" if you catch my drift. But let's calculate the pH and pOH, shall we?
First, we need to figure out the moles of HCl and nitric acid. We can use the molar mass of each compound to do that.
For HCl:
Molar mass of HCl = 1 g/mol + 35.5 g/mol = 36.5 g/mol
Moles of HCl = 15 g / 36.5 g/mol = 0.41 mol
For nitric acid (HNO3):
Molar mass of HNO3 = 1 g/mol + 14 g/mol + (3 * 16 g/mol) = 63 g/mol
Moles of nitric acid = 25 g / 63 g/mol = 0.40 mol
Now, let's find the total volume of the solution, which is given as 5.4 liters.
To find the pH, we can use the concentration of hydronium ions (H3O+), which is equal to the concentration of HCl.
pH = -log[H3O+]
Concentration of H3O+ = moles of HCl / total volume of solution
Concentration of H3O+ = 0.41 mol / 5.4 L = 0.076 M
pH = -log(0.076)
pH ≈ 1.12
To find the pOH, we can use the concentration of hydroxide ions (OH-), which is equal to the concentration of nitric acid.
pOH = -log[OH-]
Concentration of OH- = moles of nitric acid / total volume of solution
Concentration of OH- = 0.40 mol / 5.4 L = 0.074 M
pOH = -log(0.074)
pOH ≈ 1.13
So, the pH of the solution is approximately 1.12, and the pOH is approximately 1.13. I hope this helps, and that my amusing explanations made your chemistry journey a little more entertaining!
To determine the pH and pOH of a solution, we first need to calculate the concentration of H+ ions and OH- ions in the solution. We can then use these concentrations to find the pH and pOH.
Step 1: Convert the given mass of each acid to moles.
- Molar mass of HCl = 1g/mol + 35.45g/mol = 36.45g/mol
- Moles of HCl = mass / molar mass = 15g / 36.45g/mol = 0.411 mol
- Molar mass of HNO3 (nitric acid) = 1g/mol + 14.01g/mol + 48g/mol = 63.01 g/mol
- Moles of HNO3 = mass / molar mass = 25g / 63.01g/mol = 0.397 mol
Step 2: Calculate the total moles of H+ ions present in the solution.
- HCl dissociates completely in water, so 1 mol of HCl produces 1 mol of H+ ions.
- Moles of H+ ions from HCl = 0.411 mol
- HNO3 also dissociates completely in water, so 1 mol of HNO3 produces 1 mol of H+ ions.
- Moles of H+ ions from HNO3 = 0.397 mol
- Total moles of H+ ions = Moles of H+ ions from HCl + Moles of H+ ions from HNO3 = 0.411 mol + 0.397 mol = 0.808 mol
Step 3: Calculate the concentration of H+ ions.
- Concentration of H+ ions = moles of H+ ions / volume of solution
- Volume of solution = 5.4 L
- Concentration of H+ ions = 0.808 mol / 5.4 L = 0.1496 M
Step 4: Calculate the concentration of OH- ions using Kw.
- Kw (autoionization constant of water) = 1.0 x 10^-14 M^2 at 25°C
- In a neutral solution, [H+] = [OH-], so the concentrations of both ions are equal.
- [OH-] = Kw / [H+]
- [OH-] = (1.0 x 10^-14 M^2) / (0.1496 M)
- [OH-] = 6.688 x 10^-14 M
Step 5: Calculate the pH and pOH.
- pH = -log[H+]
- pH = -log(0.1496) ≈ 0.824
- pOH = -log[OH-]
- pOH = -log(6.688 x 10^-14) ≈ 13.18
Therefore, the pH of the solution is approximately 0.824, and the pOH is approximately 13.18.
To determine the pH and pOH of a solution, you first need to calculate the concentration of hydronium ions (H3O+) or hydroxide ions (OH-) in the solution.
Step 1: Calculate the number of moles of HCl and nitric acid.
The molar mass of HCl is 36.46 g/mol, and the molar mass of nitric acid (HNO3) is 63.01 g/mol. You can calculate the number of moles of each substance using the formula:
Moles = Mass / Molar Mass
For HCl:
Moles of HCl = 15 g / 36.46 g/mol
For nitric acid:
Moles of nitric acid = 25 g / 63.01 g/mol
Step 2: Calculate the total volume of the solution.
The volume of the solution is given as 5.4 L.
Step 3: Calculate the concentration of H3O+ and OH- ions.
Since HCl and nitric acid are strong acids, they dissociate completely in water to produce H3O+ ions. Therefore, the concentration of H3O+ ions from HCl and nitric acid is equal to the number of moles of HCl and nitric acid divided by the total volume of the solution:
[H3O+] = Moles of acid / Volume of solution
Step 4: Calculate the pH and pOH.
The pH is calculated using the formula:
pH = -log [H3O+]
The pOH is calculated using the formula:
pOH = -log [OH-]
Since water is neutral, the product of [H3O+] and [OH-] is equal to 1x10^-14 at 25°C. Using this relationship, you can convert the pH to pOH:
pOH = 14 - pH
Now, let's calculate the values.
Step 1: Moles of HCl = 15 g / 36.46 g/mol = 0.411 mol
Moles of nitric acid = 25 g / 63.01 g/mol = 0.396 mol
Step 2: The volume of the solution is 5.4 L.
Step 3: [H3O+] = (0.411 mol + 0.396 mol) / 5.4 L
Step 4: pH = -log [H3O+]
pOH = 14 - pH
Using these calculations, you can determine the pH and pOH of the solution.