Hello there!

Here is the solution regarding your question.

Temperature will be constant as the process mentioned is Isothermal.

Now,

PV = nRT

PV = constant

So, PiVi = PfVf       -(1)

Also, at NTP,

P = 1 atm  [1 atm = 10 N/m²]

V = 22.4 litres

T = 273 K

And,

Vf = 6 x Vi   (given)

Vf = 6 x 22.4

Putting the above information in equation 1, we get-

Pf = PiVi / Vf

Pf = 10 x 22.4 / 6 x 22.4

Pf = 0.16 x 10 N/m²

Hence, the final pressure will be 0.16 x 10 N/m²

I hope you got your answer.