Homework solution to Advanced Thermodynamics #1
1.3-2
10.0129X + 11.0093(1-X) = 10.811
X = 0.199
1.3-4
Let N be initial mole number of the sample
Total mass
0.01 kg = (1 + 0.9 + 0.8)N
3
10
kg
N = 3.7 mole
Let
'
N
be the number of moles of
2
D
to be added,
0.2
'
'
N
N
N
N
= 0.3
so
'
N
= 0.53
moles
So mass of
2
D
= 0.53
4
3
10
= 2.1
3
10
kg
1.3-5
Let X be the mole fraction and N be the mole number
342
342
18(1
)
XN
XN
X N
= 0.2
So X =1.3 %
1.3-6
Let
s
M
be the molecular mass (weight)
Let
N
be the total mole number
3
(0.1
)
(0.9
)18
10
0.1029
s
N M
N
0.1
0.07
0.036/ 0.018
N
N
So
N
= 4.67,
s
M
= 0.0584 kg
Hence NaCl is a plausible guess