Question

A sample of nitrogen occupies a volume of 250 mL at 60 oC and 550 mmHg of pressure. What will its volume be at STP?

Answer 1

ans)

from above data that

We know that PV = nRT

Where

T = Temperature ;P = pressure ; n = No . of moles ;R = gas constant ; V= Volume of the gas

As the gas remains the same , n will constant

So PV / T = constant

Thereby PV/T = P'V'/T'

Where

P = initial pressure = 500 mm Hg since 1 atm = 760 torr

                            = 500/760 atm

= 0.658 atm

V = initial volume = 250 mL

T = initial temperature = 60 ^oC = 60+273 = 333 K

P'= final pressure = 1.00 atm

V' = final volume = ?

T' = final temperature = 273 K

Plug the values we get

V' = ( PVT') / ( TP')

substitute all values in above equation

V' =0.658*250*273/333*1

= 134.86 mL

V' =approximately 135 mL

Therefore the volume occupied is 135 mL