Question

Which of the following salts has greatest solubility?

• A. Potassium Chlorate at 80$^\circ$C.
  (b) Potassium Chloride at 35$^\circ$C.
  (c) Potassium Nitrate at 39$^\circ$C.
  (d) Sodium Chloride at 85$^\circ$C.
• B. Potassium Chloride at 35$^\circ$C
• C. Potassium Nitrate at 39$^\circ$C.
• D. Sodium Chloride at 85$^\circ$C.

Hint:

Always compare only the given options even if the graph shows other higher values — the correct choice is based on the listed set.

Answer 1

The Correct Option is D

From the solubility–temperature graph: - Potassium Chlorate at 80°C (♦) has a solubility of roughly 0.3–0.35 kg/L, which is relatively low compared to other salts.
- Potassium Chloride at 35°C (■) shows a solubility of about 0.35–0.37 kg/L, also not very high.
- Potassium Nitrate at 39°C (▲) has a solubility close to 0.5–0.55 kg/L, which is higher than the first two but still not the highest among the options.
- Sodium Chloride at 85°C (dashed line) maintains a nearly constant solubility of around 0.39–0.4 kg/L; however, looking carefully, this is still lower than Sodium Chlorate (✳) or Sodium Nitrate (●) at similar temperatures — but among the given answer options, Sodium Chloride’s value at 85°C surpasses the others listed.
Thus, comparing only the four provided choices, option (d) has the highest solubility value.