Question

lerences TUTOR Combined Gas Law A 6.95 L sample of gas has a pressure of 1.5 atm and a temperature of 95°C. The sample is compressed to a volume of 5.75 L and is cooled to 39 C. Calculate the new pressure of the gas, assuming that no gas escaped during the experiment Submit Show Approach Show to Steps

Answer 1

1)
Given:
Pi = 1.58 atm
Vi = 6.95 L
Vf = 5.75 L
Ti = 95.0 oC
= (95.0+273) K
= 368 K
Tf = 39.0 oC
= (39.0+273) K
= 312 K

use:
(Pi*Vi)/(Ti) = (Pf*Vf)/(Tf)
(1.58 atm*6.95 L)/(368.0 K) = (Pf*5.75 L)/(312.0 K)
Pf = 1.62 atm
Answer: 1.62 atm

2)
Given:
Q = 1500 J
m = 496 g
C = 0.385 J/g.oC
Tf = 47.5 oC
use:
Q = m*C*(Tf-Ti)
1500.0 = 496.0*0.385*(47.5-Ti)
47.5 - Ti = 7.855 oC
Ti = 39.64 oC
Answer: 39.6 oC