Question

A canister contains 25 kPa of `CO_2`, 7.50 kPa of `N_2`, and 52.5 kPa of `O_2`. What is the total pressure within the canister?

Answer 1

This is simply the sum of the individual partial pressures...........and you can do the sum in your head.......to get `85*kPa`.

Explanation:

And this follows Dalton's law of partial pressures.....`"in a gaseous"`
`"mixture the partial pressure exerted by each gas is the same "`
`"as the pressure it would exert if it alone occupied the container."`

`"The total pressure is the sum of the individual partial pressures."`

This is an experimental gas law that has copious experimental support.

ANd thus `P_"Total"=P_(CO_2)+P_(N_2)+P_(O_2)`

`={25+7.5+52.5}*kPa`

`=85*kPa`

I think you can see from where the examiner pulled those figures.