Final answer:
To calibrate a thermometer using an ice mixture, submerge the thermometer at least 2 inches into the mixture, which allows precise measurement of the ice-water mix's temperature.
Step-by-step explanation:
To calibrate a thermometer using an ice mixture, you should follow a specific procedure to ensure precise measurement of the freezing point. When you place a thermometer into an ice mixture for calibration, the crucial aspect is to ensure the bulb or sensor of the thermometer is sufficiently submerged to accurately gauge the temperature of the ice-water mix, which should be at 0°C (32°F) on the thermometer's scale. However, the depth will depend on the design of the thermometer. For most standard laboratory thermometers, it is usually recommended that you submerge the thermometer at least 2 inches into the ice mixture to ensure it's properly surrounded by the ice-water mix and not influenced by external temperatures. This depth typically allows the thermometer to read the temperature of the mixture effectively without being too far in, where it might be influenced by ice that is not at equilibrium with the water, or too shallow, where it might be unduly influenced by air temperature.