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.
31. Based on Figure 1, at 1,150°C and 150 MPa, the solubility of CO2 in leuciitite magma is approximately how much greater than or less than the solubility of CO2 in rhyolite magma?
Your Answer is
Correct Answer is B
Explanation
Looking at Figure 1, when the abscissa is 150 MPa, the ordinate corresponding to leucitite is about 3000, and the ordinate corresponding to rhyolite is about 700. So you should choose 2300 greater.