Question

[17]. Trimix 10/50 is a gas mixture that contains 10% oxygen and 50% helium, and the rest is nitrogen. If a tank of Trinix 10/50 has a total pressure of 2.07 x 10^4 kPa, then what is the partial pressure of nitrogen?
a). 1.04 x 10^4 kPa
x b). 8.3 x 10^3 kPa
c). 2.07 x 10^3 kPa
d). 2.07 x 10^4 kPa

Answer 1

The answer is B. 8.3x10^3 kPa. The partial pressure of a specific gas in a gas mixture is equivalent to product of its mole fraction and total pressure of the mixture. Since it was stated that the mixture is 10% oxygen, 50% helium, and the rest nitrogen, it can be determined that nitrogen is 40% of the mixture. So 40% of 2.07x10^4 kPa is 8.3x10^3 kPa.