Passage III
The chemical equations in Figure 1 show what occurs when 1 formula unit of each of 3 salts dissolves in H2O.
The conductivity of a solution is a measure of its ability to conduct electricity. Figure 2 shows how the conductivity (in millisiemens per centimeter, mS/cm) of an 18°C aqueous solution of each of the 3 salts varies with concentration. Concentration is measured as millimoles of salt per liter of solution (mmol/L). A millimole is 6 x 1020 formula units of any salt.
Figure 3 shows how the conductivity of an aqueous NaCl solution at 4 temperatures with concentration (measured as % NaCl by mass).
16. According to Figure 3, which of the following NaCl solutions would have a conductivity of 200 mS/cm at 100℃?
Your Answer is
Correct Answer is J
Explanation
Look at figure 3. On the curve at 100°C, when the vertical coordinate conductivity is 200 and the horizontal coordinate concentration is 5%, then it should be 5 g NaCl in 95 g water, or 10 g NaCl in 190 g water , so choose J