Question
Mercury boils at 367oC. However, mercury thermometers are made such that they can measure temperature upto 500oC. This is done by
maintaining vacuum above mercury column in the stem of the thermometer
filling nitrogen gas at high pressure above the mercury column
filling oxygen gas at high pressure above the mercury column
filling nitrogen gas at low pressure above the mercury column
Solution
B.
filling nitrogen gas at high pressure above the mercury column
If we fill nitrogen gas at high pressure above mercury level, the boiling point of mercury is increased which can extend the range upto 500°C.
