Vapor Pressure of Benzene at 50°C: 0.028 mmHg

[ally1h]

Homework Statement

Benzene, C6H6, has a boiling point of 80 degrees Celsius. The density of benzene vapor in equilibrium with liquid benzene at 50 degrees Celsius is 1.153 g/L. What is the vapor pressure of benzene in mmHg at 50 degrees Celsius?

Homework Equations

PV=nRt
density = m/v

The Attempt at a Solution

I thought PV=nRt might cover it.. substituting d=mv into the equation and getting:
P = dRt/m
Plugging in I get:
[(1.153 g/L)(62.364 L Torr/mol K)(323 K)] / (1084.1 g/mol)
P = 21.43 Torr = 0.028 mmHg


What am I doing wrong? My professor covered what vaporization is, not how to go about getting vaporization pressure. I have a test Wednesday and I don't know how to do any of it!

 

[GCT]

Homework Statement

Benzene, C6H6, has a boiling point of 80 degrees Celsius. The density of benzene vapor in equilibrium with liquid benzene at 50 degrees Celsius is 1.153 g/L. What is the vapor pressure of benzene in mmHg at 50 degrees Celsius?

Homework Equations

PV=nRt
density = m/v

The Attempt at a Solution

I thought PV=nRt might cover it.. substituting d=mv into the equation and getting:
P = dRt/m
Plugging in I get:
[(1.153 g/L)(62.364 L Torr/mol K)(323 K)] / (1084.1 g/mol)
P = 21.43 Torr = 0.028 mmHg


What am I doing wrong? My professor covered what vaporization is, not how to go about getting vaporization pressure. I have a test Wednesday and I don't know how to do any of it!

d = m / v

 

[ally1h]

Sorry, that was a typo. I did divide when doing the actual problem. But I'm still not getting the answer. I forgot to add the choices on our homework handout.

a) 298
b) 50
c) 352
d) 462
e) 0.392


I still don't understand what I am doing incorrectly. Please help?

 

[GCT]

Sorry, that was a typo. I did divide when doing the actual problem. But I'm still not getting the answer. I forgot to add the choices on our homework handout.

a) 298
b) 50
c) 352
d) 462
e) 0.392


I still don't understand what I am doing incorrectly. Please help?

What are the units in the answers?

 

[Borek]

What is molar mass of benzene?

 

[ally1h]

The homework problem didn't give units for the answer so I have no clue. So I have no clue as to what to aim for. The molar mass of Benzene is 78.108 g/mol.

 

[ally1h]

Oh! Wow, duh, I feel stupid. I calculated the molar mass incorrectly. Haha, I've got the correct answer now! It's choice A, 298!

haha, thanks for pointing out my mistake!