A lightbulb contains Ar gas at a temperature of 295K and at a pressure of 75kPa. The light bulb is switched on, and after 30 minutes its temperature is 418 K. What is a numerical setup for calculating the pressure of the gas inside the light bulb at 418K?

Question

Assume the volume of the light bulb remains constant.

12533 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-05-09T06:27:58

The assumption is quite reasonable.........

#P_1/T_1=P_2/T_2# given constant #n#, and constant #V#, conditions that certainly obtain with a fixed volume light bulb.

And so #P_2=P_1/T_1xxT_2#

#=(75*kPa)/(295*cancelK)xx418*cancelK#

#~=100*kPa#.

Had the light bulb been sealed at normal pressure during its manufacture, what do you think might occur when it is operated?