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The critical temperature `(T_(c))` and pressure `(P_(c))` of `NO` are `177 K` and `6.48MPa`, respectively, and that of `CCl_(4)` are `550 K` and `4.56MPa`, respectively. Which gas `(a)` has the smaller value for the van der Waals constant `b`, `(b)` has the smaller value for constant `a`, `(c)` has the larger critical volume, and `(d)` is most nearly ideal in behaviour at `300 K` and `1.013MPa`. |
Answer» The given values are `{:(T_(c)(NO)=177K, T_(c)(C Cl_(4))=550 K), (P_(c)(NO)=6.485MPa, P_(c)(C Cl_(4))=4.56MPa):}` `a` Since `(P_(c))/(T_(c))=(a//27b^(2))/(8a//27Rb)=(R )/(8b)`, `b=(T_(c)R)/(8P_(c))` Thus, `b(NO)=((177K)(8.314MPadm^(3)K^(-1)mol^(-1)))/((8)(6.485MPa))` `=28.36 cm^(3)mol^(-1)` and `c(C Cl_(4))=((550 K)(8.314MPa cm^(3)K^(-1)mol^(-1)))/((8)(4.56MPa))` `=125.35 cm^(3)mol^(-1)` Hence, `b(NO)ltb(C Cl_(4))`. `b` Since `a=27P_(c)b^(2)`, `a(NO)=(27)(6.485MPa)(28.36 cm^(3)mol^(-1))^(2)` `=140.827 kPa dm^(6) mol^(-2)` `a(C Cl_(4))=(27)(4.56MPa)(125.35 cm^(3)mol^(-1))^(2)` `=1934.538kPa dm^(6) mol^(-2)` Hence, `a(NO)lta(C Cl_(4))`. `c` Since `V_(C)=3b`, `V_(C)(NO)=3xx(28.36 cm^(3)mol^(-1))` `=85.08 cm^(3) mol^(-1)` `V_(C)(C Cl_(4))=3xx(125.35 cm^(3)mol^(-1))` `=376.05 cm^(3) mol^(-1)` Hence, `V_(C)(NO)ltV_(C)(C Cl_(4))`. `d` `NO` is more ideal in behaviour at `300 K` and `1.013 MPa` because its critical temperature is less than `300 K`, whereas the corresponding critical temperature of `C Cl_(4)` is greater than `300 K`. |
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