Abuffer solution is made by dissolving 0.45 moles of a weak acid (ha) and 0.33 moles of koh into 710 ml of solution. what is the ph of this buffer? ka = 6x10-6 for ha.

The pH of the buffer solution is 5.08.

Solution:

Volume of buffer solution=710 mL = 0.710 L (1L=1000ml)

ph of the buffer can be calculated by using buffer equation:

...(1)

On substituting values in (1)  we get

The pH of the buffer solution is 5.08.

5.66

Given:

Question:

What is the pH of this buffer?

The Process:

The balanced equation for this reaction is:

Initial:      0.45     0.33         -          -

Change:  0.33     0.33     0.33    0.33

Final:       0.12         -        0.33    0.33

          (excess)  (limiting)

When 0.45 moles of HA react with 0.33 moles of KOH, 0.33 moles of KA are produced, and 0.12 moles of HA remain unreacted.

At the end of the above reaction, the buffer solution (or buffer system) is composed of weak acids mixed with their conjugate base salts.

To calculate the specific pH of a given buffer, we need using The Henderson-Hasselbalch equation for acidic buffers:

where,

Let us prepare the concentrations.

From KA salt ionization:   we observe that there is one A⁻ ion or the valence is 1.

Hence, , so

Let us calculate the pH of this buffer.

Recall this:

Thus, the pH of this buffer is 5.66 and represents an acidic buffer solution.

_ _ _ _ _ _ _ _ _ _

Notes:

A buffer solution is one that naturally resists changes in pH when lesser quantities of an acid or an alkali are carefully added to it.  

it would be b. 6co2 + 6h2o --> c6h12o6 + 6o2

explanation:

0.07 g/cm³

1.37 g/cm³