CHE151 : Chemistry Practices Questions for exam


Question 1 : Calculate
a) EC-C b) EC?N
?H form of CH3CN = 87.86 KJ/mole
?H form of C2H6 = -83.68 KJ/mole
?Hsub of graphite = 719.65 KJ/mole
Enthalpy of dissociation of N2 = 945.58 KJ/mole
Enthalpy of dissociation of H2 = 435.14 KJ/mole
C-H bond enthalpy = 414.22 KJ/mole

Question 2 : Write the degree of freedom for one, two, three phases of 1,2, and 3 component system.

Question 3 : Derive the phase rule for a system in which one compound is missing from the phase number1. There are P phases and each phase has C component except phase number 1.

Question 4 : Draw the phase diagram of water. Explain how skaters skates on ice using this diagram. Write degree of freedom at triple point, melting curve, boiling curve and sublimation curves and also in the region.

Question 5 : For the equilibrium PCl5(g) ----PCl3+ Cl2(g) at 298 K, Kc = 1.8x10-7. What is ?Go for the reaction. R = 8.314 J/Kmole

Question 6 : Define

a)Molecularity
b) Order of reaction

Question 7 : Write the unit of rate constant for
a) Zero b) 1st c) 2nd d) 3rd order of reaction.