GCE AS Physics (Thermal Physics)

I have few questions from the book "International A/AS Level Physics" By Chris Mee, Mike Crundell, Brian Arnold and Wendy Brown.

In Thermal Physics (Page 163):

"In the ideal gas equation PV=nRT, could one use values of Celsius temperature instead of thermodynamic temperature by using an appropriate value R of the molar Gas constant?"

R = 8.3 J K-1 Mol-1.

Another question i have from the same page :

"The kinetic theory leads to the expression:

*= 3/2 KT

for the average kinetic energy of the molecule of a gas. The constant K does not depend on the type of molecule. Can this result be true for both Hydrogen and Chlorine? (The mass of a chlorine molecule is about 35 times that of a hydrogen molecule"

* means : Mean Kinetic energy.



Another question i wish to ask:

"Over the range of temperature between about 250K and 450K, the resistance R of a certain platinum wire is given by

R = a+bT+cT2 (cT2 = cT squared *The T is squared*)

Where T is the thermodynamic temperature and

a= -1.32 Ohm
b= +4.31 * 10 to the power -2 ohm per kalvin
c= -6.04 * 10 to the power -6 ohm per kalvin squared

(A) A certain solid melts at 150 Celsius. Calculate the resistance of the wire at this temperature.

The answer to A is 15.8 Ohm, i already answered this part, i need help in part (B)

(B) If the wire were used as a resistance thermometer, calculate the melting point of the solid on the empirical centigrade scale of this thermometer.

What should i do to find the answer in this part ???


My last question is :

"The mass of an oxygen molecule is 16 times the mass of a hydrogen molecule. Equal masses of the hydrogen and oxygen gases are mixed and are allowed to come to equilibrium. Calculate:

(A) The ratio of numbers of molecules.
(B)The ratio of the average Kinetic energy per molecule.