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).
14. The conductivity of an aqueous solution that is 15% NaCl by mass was 100 mS/cm. The temperature of the solution was most likely:
Your Answer is
Correct Answer is F
Explanation
Looking at table 3, we can see that the higher the temperature, the higher the conductivity of NaCl solution with the same concentration. (15%, 100) This point is below the curve of 20°C, it is inferred that the temperature is lower than 20°C at this time