Final answer:
Iodine's efficacy is determined by temperature, pH, and concentration, with ideal conditions being temperatures between 60-80 °C (140-176 °F) or 80-122 °C (176-250 °F), a pH of 9 or higher, and concentration depending on the application.
Step-by-step explanation:
The question pertains to the conditions necessary for the effectiveness of iodine, specifically its minimum temperature, pH, and concentration. Iodine requires a specific set of conditions to be effective. Temperature is a crucial factor, with a range of 60-80 °C (140-176 °F) generally being suitable. However, higher temperatures of 80-122 °C (176-250 °F) are also mentioned. Regarding pH levels, iodine requires a pH of 3 or above, and ideally, should be at a pH of 9 or higher to remain stable and effective. The concentration of iodine is also critical; blood plasma normally contains 4 to 10 µg/100 ml, but for applications such as disinfection, the required concentration might differ significantly and would be specific to the context. Additionally, extremities in salt concentration (at least 0.2 M) and high sugar concentration affect iodine's stability and efficacy.