2.
a) Q1=ν*Cv(T2-T1)=5/2ν*R(T2-T1)=5/2(p2V2-p1V1)=5/2V(p2-p1)=5/2VΔp
V=100 l=0,1 m³
Δp=P2-p1=140-100=40 kPa=40*10³ Pa
Q1=5/2VΔp=5/2*0,1*40*10³=5/2*4*10³=10*10³=10⁴ J=10 kJ
b) L=0 (in transformarea izocora , volumul nu variaza si gazul nu schimba lucru mecanic cu mediul exterior )
c) ΔU=Q1-L=10-0=10 kPa
1.
ν=m/μ
μ=14*2=28 g/mol=0,028 kg/mol
V=2 l=0,002 l
V₀=22,44 l/mol=22440 m³/l
m/μ=V/V₀=>m=μV/V₀=0,028*0,002/22440=0,028*0,001/11220=0,001*0,001/400,71=10⁻⁶*40071*10²≈ 4 kg
ν=m/μ=4/0,028≈143 molecule
c=1040 J/kg*K
C=mc=4*1040=4160 J/K
C=Q1/ΔT =>Q1=CΔT
Cp=Q1/νΔT=CΔT/νΔT=C/ν=4160/143≈29 J/mol*K
Cp=Cv+R=>Cv=Cp-R=29-8,314≈21 J/mol*K
γ=Cp/Cv=29/21
a) Q1=νCVΔT=ν*γR/(γ-1)*(T2-T1)=γ/(γ-1)(p2V2-p1V1)=γ/(γ-1)VΔp=5800 J
b) L=0
c) ΔU=Q1=5800 J
1 nu stiu daca e corect
