A tank contains 36.5 g of O₂ and 46.4 g of N₂ at a pressure of 3.64 atm. What is the pressure of O₂ in the tank (in atm)?

Partial pressure O₂ = 1.49 atm

Explanation:

We can solve this, by the mole fraction concept.

Mole fraction = Moles of gas / Total moles

We can also define mole fraction as: Partial pressure of a gas / Total pressure

Total moles = Moles of O₂ + Moles of N₂

36.5 g. 1 mol / 32g + 46.4 g . 1mol /28g = 2.79 moles

1.14 moles O₂ + 1.65 moles N₂ = 2.79 moles

Partial pressure O₂ / Total pressure = Moles of O₂ / Total moles

Partial pressure O₂ = (Moles of O₂ / Total moles) . Total pressure.

We replace: (1.14 mol / 2.79 mol) . 3.64 atm = 1.49 atm

Partial pressure O₂ = 1.49 atm

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.