Final answer:
An alcohol thermometer cannot be used to measure the temperature of boiling water because the alcohol expands quickly with increasing temperature, making it impossible to accurately measure the temperature beyond the scale on the thermometer.
Step-by-step explanation:
An alcohol thermometer cannot be used to measure the temperature of boiling water because the alcohol inside the thermometer expands rapidly with increasing temperature. When the temperature of boiling water is reached, the alcohol would expand and push the column of liquid past the scale on the thermometer, making it impossible to accurately measure the temperature.
A typical alcohol thermometer consists of a glass bulb that contains alcohol with a red dye. As the temperature increases, the liquid from the bulb is forced into a narrow tube, producing a large change in the length of the column for a small change in temperature. However, when the temperature reaches the boiling point of water, the added heat is used to evaporate the water, and the temperature does not increase further. To measure the temperature of boiling water, a different type of thermometer, such as a liquid crystal or pyrometer, would be more suitable.