Answer:

pV=nRT or pV=

M

w

RT or M=

V

w

p

RT

or M=d

p

RT

Here, d=1.964g/dm

3

=1.964×10

−3

g/cc

P = 76 cm = 760 mm Hg = 1 atm

R = 0.0821 L atm K

−1

mol

−1

=82.1 cc atmK

−1

mol

−1

T=273K

∴M=

1

1.964×10

−3

×82.1×273

=44

The molecular weight of CO

2

is 44.

So, the gas is CO

2

.