The air pressure in Denver, Colorado is about 83 percent of the air pressure in Miami Beach, which is at about sea level. Given that the air pressure in Miami Beach is 760 mm Hg and oxygen makes up 21 percent of the air in Miami Beach, what are the percentage of oxygen and the partial pressure of oxygen in Denver

Explanation:

mass ratio of oxygen and nitrogen in air at Miami

= 21 : 79

ratio of their moles

=     ( mol weight of oxygen is 32 and of nitrogen is 28 )

=  .65625 : 2.8214

= 1 : 4.3

This ratio will also be maintained in the air of Denver though total pressure decreases there.

Partial pressure of oxygen in air at both the places

mole fraction of oxygen

=

= .18868

partial pressure of oxygen at Denver

= .18868 x .83 x 760

= 119 mm.

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)