Some freedivers hyperventilate (breathe rapidly and deeply) before diving. Hyperventilation can change the concentration of CO 2 CO2 in the blood and may increase the length of time that a person feels like he or she can hold his or her breath. How does hyperventilation affect blood pH?

Explanation:

It is a state of breathing process when a person start breathing very fast . When a person is under excessive stress or he is  paniky or he suffers from anxiety , he start breathing fast . Fast breathing results in excessive loss of carbon dioxide in the body.

Carbon dioxide forms acidic solution when dissolved in water . When level of carbon dioxide reduces in the blood , it becomes less acidic . In other words it becomes more basic. Therefore the level of pH of blood  is  increased .

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.