Passage I
A mineral hydrate (MH) is an ionic compound that has associated H2O molecules. Dehydration (removal of all H2O) of an MH produces its anhydrous salt (an ionic compound that has no associated H2O molecules), which may differ in color from the MH. Table 1 shows, for each of 4 MHs, the chemical formula of one formula unit of the MH, its color, and the color of its anhydrous salt.
Figure 1 shows the mass of a sample that was converted from chalcanthite to CuSO4 as its temperature was increased from 0°C to 350°C.
Table 2 shows the solubility in H2O of each anhydrous salt at 20°C, 40°C, 60°C, and 80°C.
4. Based on Figure 1, as the sample was heated from 0°C to 100°C. the mass of the sample decreased by approximately:
Your Answer is
Correct Answer is G
Explanation
Look at figure 1, when heated from 0 to 100 degrees, the mass changes from the original 100 g to about 86 g, so the mass decreases by 100-86=14 g