Question

A solution is prepared by adding 30.8 ml of 0.061 m hbr to 184.2 ml of 0.39 m hi. calculate [h ] and the ph of this solution. hbr and hi are both considered strong acids.

H+=
Ph=

Answer 1

To calculate the [H3O+] concentration and the pH of the solution, determine the excess acid and calculate its concentration. The [H3O+] concentration is equal to the concentration of the excess acid, which in this case is HI. The pH can be calculated using the formula pH = -log[H3O+].

Step-by-step explanation:

To calculate the [H3O+] concentration and the pH of the solution, we need to apply the principles of titration and acid-base reactions. Given that HBr and HI are both strong acids, they dissociate completely in water.

The balanced equation for the reaction is:

HBr + HI → H2 + IBr

To calculate the [H3O+] concentration, we need to determine which acid is in excess. Since 30.8 mL of 0.061 M HBr is added to 184.2 mL of 0.39 M HI, we can calculate the moles of each acid:

moles of HBr = volume (L) × concentration (M) = 0.0308 L × 0.061 M = 0.00188 moles

moles of HI = volume (L) × concentration (M) = 0.1842 L × 0.39 M = 0.0718 moles

Since HI has more moles than HBr, it is the excess acid. Thus, all of the HBr will react with HI, forming water and IBr. This means that the [H3O+] concentration is equal to the concentration of HI:

[H3O+] = 0.39 M

The pH of a solution can be calculated using the formula:

pH = -log[H3O+]

Substituting the [H3O+] concentration:

pH = -log(0.39) ≈ -(-0.407) ≈ 0.407

Therefore, the [H3O+] concentration of the solution is 0.39 M, and the pH is approximately 0.407.