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?
Explanation:
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
1
×
T
2
=
75
⋅
k
P
a
295
⋅
K
×
418
⋅
K
≅
100
⋅
k
P
a
.
Had the light bulb been sealed at normal pressure during its manufacture, what do you think might occur when it is operated?
