Work out dalton law of partial pressures instantly with clear inputs, formula shown and shareable results.
Dalton's law says each gas in a mixture exerts its own pressure independently and the total is their sum. 60, 25 and 15 kPa give 100 kPa, with mole fractions of 60%, 25% and 15%. This is why the oxygen partial pressure at altitude matters more than the percentage, which stays at 21% all the way up.
Dalton's law
P(total) = p1 + p2 + p3 + ...
Mole fraction
x(i) = p(i) / P(total)
Because total pressure falls, so oxygen's partial pressure falls with it. At 5500 m it is about half its sea-level value.
Yes. Saturated vapour pressure must be subtracted before applying the dry-gas fractions, which matters in respiratory physiology and gas collection over water.