A buffer solution contains 0.306 M C6H5NH3Br and 0.418 M C6H5NH2 (aniline). Determine the pH change when 0.124 mol HCl is added to 1.00 L of the buffer.

The pH change of the buffer is 0.30

Explanation:

To calculate the pH of basic buffer, we use the equation given by Henderson Hasselbalch:

       .....(1)

We are given:

= negative logarithm of base dissociation constant of aniline  = 9.13

pOH = ?

Putting values in equation 1, we get:

To calculate pH of the solution, we use the equation:

To calculate the molarity, we use the equation:

Moles hydrochloric acid solution = 0.124 mol

Volume of solution = 1 L

Putting values in above equation, we get:

The chemical reaction for aniline and HCl follows the equation:

Initial:           0.418        0.124           0.306

Final:             0.294          -                0.430

Calculating the pOH by using using equation 1:

= negative logarithm of base dissociation constant of aniline  = 9.13

pOH = ?

Putting values in equation 1, we get:

To calculate pH of the solution, we use the equation:

Calculating the pH change of the solution:

Hence, the pH change of the buffer is 0.30

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !