Answer:
a. 0 J
b. - 9.5J
c. - 17.8 J
Explanation:
part a (against a vacumm)
Data given:
initial volume V1 = 26.7 mL
Final volume V2 = 89.3 mL
work done w = ?
temperature = constant
Solution:
formula will be used
w = - PΔV
where
ΔV = V2 -V1
so the above equation will be written as
w = - P (V2 - V1) . . . . . . (1)
as we are calculating work against vacuum so the pressure will be 0 atm.
So,
P = 0 atm
Put values in above equation 1
w = - [(0 atm)(89.3 mL - 26.7 mL)
w = - [(0 atm)(62.6mL)
w = - (0)J
w = 0 J
so the work done will be 0
_________________
part b (against constant pressure of 1.5)
Data given:
initial volume V1 = 26.7 mL
Convert mL to L
1000 mL = 1 L
26.7 mL = 26.7/1000 = 0.0267 L
Final volume V2 = 89.3 mL
Convert mL to L
1000 mL = 1 L
89.3 mL = 89.3/1000 = 0.0893 L
work done w = ?
Pressure constant = 1.5 atm
Solution:
formula will be used
w = - PΔV
where
ΔV = V2 -V1
so the above equation will be written as
w = - P (V2 - V1) . . . . . . (1)
Put values in above equation 1
w = - [(1.5 atm)(0.0893 L - 0.0267 L)
w = - [(1.5 atm)(0.0626 L)
w = - (0.0939 atm.L)
w = - 0.0939 atm.L
convert atm.L to J
1 atm.L = 101.3 J
0.0939 atm.L = 0.0939 x 101.3 = 9.5 J
so the work done will be - 9.5 J
___________
Part c ( constant pressure of 2.8 atm)
Data given:
initial volume V1 = 26.7 mL
Convert mL to L
1000 mL = 1 L
26.7 mL = 26.7/1000 = 0.0267 L
Final volume V2 = 89.3 mL
Convert mL to L
1000 mL = 1 L
89.3 mL = 89.3/1000 = 0.0893 L
work done w = ?
Pressure constant = 2.8 atm
Solution:
formula will be used
w = - PΔV
where
ΔV = V2 -V1
so the above equation will be written as
w = - P (V2 - V1) . . . . . . (1)
Put values in above equation 1
w = - [(2.8 atm)(0.0893 L - 0.0267 L)
w = - [(2.8 atm)(0.0626 L)
w = - (0.1753 atm.L)
w = - 0.1753 atm.L
convert atm.L to J
1 atm.L = 101.3 J
0.1753 atm.L = 0.1753 x 101.3 = 17.8 J
so the work done will be - 17.8 J
