Question

The bulk modulus of the benzene at 0ºC and normal atmospheric pressure is 1,11*10^5 atm. Which pressure variation ( Δp) is necessary to avoid a volume variation of the benzene, when its temperature increases 1ºC.
More info:
B = - (Δp / Δv/v) ; Thermal expansion coefficient of benzene : 1,24* 10^-3

Answer 1

@nincompoop

Answer 2

As the benzene will expand, it will exert an outward pressure. This will result in the generation of outward force. In order to prevent its expansion, the effect of this outward pressure will have to be nullified by applying an equal inward pressure.
So the problem is to find the outward pressure generated in the benzene due to its expansion as a result of temperature variation.
We know that\[\Delta V =V \gamma \Delta T\]
Where "Delta T" is temperature change

"V" is initial volume

"Delta V" is volume change due to expansion

"gamma" is coefficient of volume expansion

In the question "Delta T" = 1 K
"gamma" = 1.24 *10^-3

From here find the value of
\[\Delta V \div V = \gamma \Delta T\]

We know that excess pressure developed =\[\Delta P = E * \Delta V / V\]

E is the bulk modulus given to us.
Find the value of "Delta P" .
From the arguments at the beginning, this is the pressure required to prevent the expansion.