Passage V
When rocks are melted at very high temperatures beneath Earth's surface, magma (molten rock) is formed. The gases CO2, and H2O can dissolve in magma. Figure 1 shows, for 4 different magmas (leucitite, basanite, rhyolite, and tholeiitic basalt), how the solubility of CO2 in the magma at 1,150°C varies with pressure (in megapascals MPa).
Figure 2 shows, at 3 different pressures, how the solubility of CO2 in rhyolite magma varies with temperature.
Figure 3 shows, at 4 different pressures, how the solubility of CO2, in rhyolite magma at 750°C varies with the weight percent of H2O in the magma.
28. According to Figure 2, at 300 MPa, the solubility of CO2 in rhyolite magma is closest to 2,000 ppmw at which of the following temperatures?
Your Answer is
Correct Answer is H
Explanation
Look at Figure 2, find the line of 300 MPa, the ordinate is locked at 2000, and the corresponding abscissa should be 800 °C.