Question

Carbon dioxide, when it is at -145 degreesC has a density of 2.54 g/L. What is the pressure in torr??

Answer 1

Answer: The pressure in torr is 461 torr

Step-by-step explanation:

To calculate the relation of density and molar mass of a compound, we use the ideal gas equation:

PV=nRT

P = pressure

V = Volume

n = number of moles

R = gas constant = 0.0821 Latm/Kmol

T = temperature =
`-145^0C=(273-145)K=128K`

Number of moles (n) can be written as:

`n=(m)/(M)`

where, m = given mass

M = molar mass = 44 g/mol

`PV=(m)/(M)RT\\\\PM=(m)/(V)RT`

where,

`(m)/(V)=d`

where d = density = 2.54 g/L

The relation becomes:

PM=dRT

`P=(dRT)/(M)`

`P=(2.54* 0.0821* 128)/(44)=0.607atm`

`P=461torr` (760torr=1atm)

Thus the pressure in torr is 461 torr