Suppose that 0.10 liter of 0.50 molar hydrochloric acid is added to 0.040 liter of the buffer
prepared in (b). Compute the hydrogen ion concentration of the resulting solution.
First, let's find the moles of HCl added:
moles HCl = volume (in liters) x molarity
moles HCl = 0.10 L x 0.50 mol/L
moles HCl = 0.05 mol
Next, let's find the moles of the buffer components in 0.040 L:
moles of HA = volume (in liters) x molarity
moles of HA = 0.040 L x 0.50 mol/L
moles of HA = 0.020 mol
moles of A- = volume (in liters) x molarity
moles of A- = 0.040 L x 0.50 mol/L x 0.10
moles of A- = 0.002 mol
To calculate the hydrogen ion concentration of the resulting solution, we need to find the total moles of H+ and the total volume of the solution. The HCl will completely dissociate in water, so all of its moles will contribute to the hydrogen ion concentration:
total moles of H+ = 0.05 mol (from HCl) + 0.002 mol (from A-)
total volume = 0.10 L + 0.040 L = 0.14 L
Now we can calculate the hydrogen ion concentration:
[H+] = moles of H+ / volume of solution
[H+] = (0.05 mol + 0.002 mol) / 0.14 L
[H+] = 0.37 M
Therefore, the hydrogen ion concentration of the resulting solution is 0.37 M.
To find the hydrogen ion concentration of the resulting solution, we need to consider the reaction between hydrochloric acid (HCl) and the buffer solution.
Since hydrochloric acid is a strong acid, it completely dissociates in water to form hydronium ions (H3O+) and chloride ions (Cl-):
HCl -> H+ + Cl-
The buffer solution also contains an acid and its conjugate base, which can react with the additional HCl to maintain a stable pH.
Let's break down the steps to calculate the hydrogen ion concentration:
1. Calculate the moles of HCl:
Moles = Concentration × Volume
Moles = 0.50 mol/L × 0.10 L
Moles = 0.05 moles
2. Determine the total volume of the solution:
Total volume = Volume of buffer + Volume of HCl
Total volume = 0.040 L + 0.10 L
Total volume = 0.14 L
3. Calculate the hydrogen ion concentration:
Hydrogen ion concentration = Moles / Total volume
Hydrogen ion concentration = 0.05 moles / 0.14 L
Hydrogen ion concentration = 0.357 mol/L
Therefore, the hydrogen ion concentration of the resulting solution is 0.357 mol/L.