PASSAGE II
A chemist conducted an experiment using 3
gases: hydrogen (H2), carbon monoxide (CO), and
oxygen (O2). For each gas, the chemist performed
the following steps in order:
1. She fitted a 5 liter (L) stainless steel vessel with a
cap that included a vacuum pump, a gas inlet valve,
and an internal pressure-temperature display. (The
internal pressure-temperature display showed both
the real-time pressure and temperature inside the
vessel after the cap was fitted.)
2. She vacuumed air out of the vessel until the
internal pressure was 0.00 kilopascal (kPa).
3. She placed the vessel on a scale and calibrated
the scale to 0.00 gram (g).
4. She added a predetermined amount of H2, CO, or
O2 to the vessel.
5. When the internal temperature of the vessel
reached equilibrium at 23 degrees Celsius (°C), she
recorded the mass of the gas inside the vessel and
the pressure inside the vessel.
6. Steps 1-5 were repeated several times with
different amounts of CO, H2, and O2.
Steps 1-6 were then repeated using a 10 L vessel,
instead of the 5 L vessel. All results are set forth in
Figures 1 and 2.
Figure 1
Figure 2
Based on Figure 2, how many grams of CO
would the chemist have to add to the 10 L vessel
in order to create approximately 50 kPa of
pressure inside the vessel?
F.
Between 0 and 125 grams
G.
Between 125 and 250 grams
H.
Between 250 and 375 grams
J.
Between 375 and 500 grams
To determine the number of grams of CO needed to create approximately 50 kPa of pressure inside the 10 L vessel, we can refer to Figure 2. Looking at the graph, we can see that at a pressure of 50 kPa, the mass of CO inside the vessel is approximately 300 grams. Therefore, the chemist would need to add between 250 and 375 grams of CO to the 10 L vessel in order to create approximately 50 kPa of pressure.
Therefore, the correct answer is H. Between 250 and 375 grams.