The correct options are
A X = He, Y = Ne, Z = Ar at 323 K
B He is plotted at X = 1000 K, Y = 500 K, Z = 100 K
C X, Y, Z have RMS speeds marked
a) At any given temperature T,
molecular speed ∝√1M Mass of the gases follows the order:
Ar>Ne>He So the right inswer can be X = Ar, Y = Ne, Z = He at 323 K.
b) For a given gas,
molecular speed ∝√T As
T↑es, c↑es Correct order should be:
X>Y>Z c) Most probable speeds are marked on the graph.
Let say 1, 2 and 3 are maxima of the graph X, Y and Z respectively. For that slop is zero, i.e.
d(f(c))dc=0 That is not rms.
d) As mass increases, intermolecular forced increases hence
Tc increases.