We can measure the temperature of 100°C with a mercury thermometer but not with an alcohol thermometer. Why?
We all know that the FP of alcohol is - 1150C and BP is780C. But the FP of mercury is - 350Cand BP is3570C. So, mercury has a normal physical state at 1000Cand can measure temperature. But, alcohol starts boiling if the temperature raised to780C. So, it changes to a gasstate at1000Cand cannot measure temperature. Hence, wecan measure the temperature of1000C with a mercury thermometerbut not with an alcohol thermometer.