Question

A mixture of 0.220 moles co, 0.350 moles h2 and 0.640 moles he has a total pressure of 2.95 atm. what is the partial pressure of h2?

Answer 1

Answer : The partial pressure of
`H_2` is, 0.853 atm

Solution :

First we have to calculate the mole fraction of
`H_2` in the mixture.

Formula used :

`X_(H_2)=(n_(H_2))/(n_(H_2)+n_(CO)+n_(He))`

Now put all the given values in this formula, we get

`X_(H_2)=(0.35)/(0.22+0.35+0.64)=0.289`

Now we have to calculate the partial pressure of
`H_2`

Formula used :

`p_(H_2)=X_(H_2)* P_T`

where,

`P_T` = total pressure = 2.95 atm

`p_(H_2)` = partial pressure of nitrogen gas = ?

`X_(H_2)` = mole fraction of nitrogen gas = 0.289

Now put all the given values in the above formula, we get

`p_(H_2)=0.289* 2.95atm`

`p_(H_2)=0.853atm`

Therefore, the partial pressure of
`H_2` is, 0.853 atm

Answer 2

P = 2.95 atm, total pressure
N = 0.220 + 0.350 + 0.640 = 1.21 moles, total moles

According to Dalton's Law, the partial pressure of H₂ is
(0.350/1.21)*(2.95 atm) = 0.8533 atm

Answer: 0.853 atm