An ordinary mercury-in-glass thermometer is calibrated. In the ice water bath, the mercury level is 2.45 cm above the bulb. In boiling water at 1.00 atm pressure the mercury level is 17.75 cm above the bulb. What is the Celsius temperature when the level in 12.70 cm above the bulb?

Answer 1

---- = 17.75 = 100 C
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-------2.45 cm = 0 C
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O bulb
So zero is 2.45 cm above bulb and 100 C is 17.75 above the bulb; therefore, the 100 C mark is 15.3 cm (17.75-2.45) above the 0 C.
Where is the 12.70 cm? That is 12.70-2.45 - 10.25 cm above the zero mark. So the T should be
100 C x (10.25/15.3) = ?