A tank contains a mixture of nitrogen, carbon dioxide, and oxygen with a total pressure of 150 kPa. What is the partial pressure of oxygen if the partial pressure of the nitrogen is 90 kPa and the partial pressure of carbon dioxide is 34 kPa?

116 kPa

26 kPa

124 kPa

60 kPa

1 answer

To find the partial pressure of oxygen in the tank, we can use Dalton's Law of Partial Pressures, which states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the individual gases.

Given:

  • Total pressure, \( P_{total} = 150 , \text{kPa} \)
  • Partial pressure of nitrogen, \( P_{N_2} = 90 , \text{kPa} \)
  • Partial pressure of carbon dioxide, \( P_{CO_2} = 34 , \text{kPa} \)

We need to find the partial pressure of oxygen, \( P_{O_2} \).

Using the equation:

\[ P_{total} = P_{N_2} + P_{CO_2} + P_{O_2} \]

Substituting the known values:

\[ 150 , \text{kPa} = 90 , \text{kPa} + 34 , \text{kPa} + P_{O_2} \]

Now combine the pressures of nitrogen and carbon dioxide:

\[ 150 , \text{kPa} = 124 , \text{kPa} + P_{O_2} \]

Now, solve for \( P_{O_2} \):

\[ P_{O_2} = 150 , \text{kPa} - 124 , \text{kPa} \] \[ P_{O_2} = 26 , \text{kPa} \]

Thus, the partial pressure of oxygen is \( \boxed{26 , \text{kPa}} \).