Two ideal gas thermometer `A` and `B` use oxygen and hydrogen respectively . The following observations are made:
Temperature, Pressure therometer A, Pressure therometer B
Triple point of water, `1.250xx10^(5)Pa`, `0.200xx10^(5)Pa`
Normal melting point of sulphur, ` 1.797xx10^(5)Pa`, `0.287xx10^(5)Pa`
(a) What is the absolute temperature of normal melting point of sulphur as read by thermometers `A` and `B` ?
(b) What do you think is the reason for the slightly different answers from `A` and `B` ? (The thermometers are not faulty). what further procedure is needed in the experiment to reduce the discrepancy between the two readings.

Explanation

(a) `T_(Lambda) = 392.69 K, T_(B) = 391.98 K`, (b) The discrepancy arises because the gases are not perfectly ideal To reduce the discrepancy. readings should be taken for lower and lower pressures and the plot between temperature measured versus absolute pressure of the gas at triple point should be extrapolated to obtain temperature in the limit pressure tends to zero, when the gases approach ideal gas behaviour.