Question

A gas mixture is contained in a sealed flask at atmospheric pressure, 101.33kPa. When all the carbon dioxide is chemically removed from the sample, keeping the same temperature, the final pressure is 67.89 kPa. What percentage of the molecules of the original sample was carbon dioxide?

Answer 33%, please show work

Answer 1

Solution:

We had 101.33kPa gas mixture. All carbon dioxide was removed and remaining gas was 67.89kPa.

We can add, subtract physical quantities of same units, here Pressure.

Pressure exerted by CO2 = 101.33 - 67.89

                                                  = 33.44 kPa

% of CO2 in original sample = 33.44% of 101.33

                                                  = 33.88 %

33.88% CO2 was in original sample.