Question

Please help me, I don’t understand!!
The pressure in a car is 35psi on a winter day when the temperature is 0 degrees Celsius. What is the pressure in the same car tire, assuming the volume of the tire has not changed, on a summer day when the temperature is 30 degrees Celsius. (Use gay-lussac’s law.) show all calculations.

Answer 1

35psi is gauge pressure. Add atmospheric pressure to find true pressure: 49.6PSI
Now use P1/T1=P2/T2
convert temp to kelvins
P2=P1 (T2/t1)=49.6 * (303/273)=55PSI
now convert that absolute pressure to gauge
55-14.6=40.4PSI
This assumes atmospheric pressure did not change with temp.

Answer 2

Thanks bobpursley