States of Matter (Gaseous and Liquid States)

From ideal gas equation we know,
PV=nRT
⇒PV=‌

W

M

RT
⇒P=‌

W

V

⋅‌

RT

M

⇒P=d⋅‌

RT

M

[∵d=‌

W

V

]
For a fixed amount of gas at a fixed temperature, M and T is constant.
∴P∝d
So graph between pressure (P) and density (d) is a straight line.
Also, ‌

P

d

=‌

RT

M

⇒‌

P

d

∝T‌ [as ‌R,M=‌ constant ‌]
∴ When temperature T increases then slope of graph between P and d increases.
As T3>T2>T1 then slope of T3 will be highest then T2 and then T1.
So, graph (B) is the right graph.