Is the pH of the blood different in artery and vein?having dissolved carbon-dioxide in the veins is the pH lower in the veins?

An acid can donate hydrogen ions, a base can accept
hydrogen ions into solution. The acid-base balance in the body is maintained by several
complicated mechanisms.

One way in which acid-base balance
is maintained are by the use of buffer systems. Buffers help to change the pH of the
blood. For example, the hemoglobin/oxyhemoglobin system is a very effective body buffer.
In erythrocytes, free hydrogen ions bind with hemoglobin . For every free hydrogen ion
that binds with hemoglobin, a corresponding bicarbonate ion diffuses out of the red
blood cell into the plasma. Also, chloride ions are exchanged with bicarbonate
ions.

When blood leaves the venous system, the bicarbonate
and chloride ions exchange. This results in a higher chloride concentration in the
venous blood, hence, the pH is changed. Venous blood will have a lower pH than arterial
blood. Additionally, increased levels of CO2 in the venous system also play a role in
regulating pH.