Related InterviewSolutions

• Calculate `DeltaU and DeltaH` when `10dm^(3)` of helium at NTP is heated in a cylinder to `100^(@)C`, assuming the the gas behaves ideally. `(C_(V)=3//2R)`
• Calculate q,w, `DeltaU` and `DeltaH` for the reversible isothermal expansion of one mole of an ideal gas at `127^(@)C` from a volume of `10dm^(3)` to `20dm^(3)`.
• The standard Gibbs free energies for the reaction at `1773K` are given below: `C(s) +O_(2)(g) rarr CO_(2)(g), DeltaG^(Theta) =- 380 kJ mol^(-1)` `2C(s) +O_(2)(g) hArr 2CO(g),DeltaG^(Theta) =- 500 kJ mol^(-1)` Discuss the possibility of reducing `AI_(2)O_(3)` and `PbO` with carbon at this temperature, `4AI +3O_(2)(g) rarr 2AI_(2)O_(3)(s),DeltaG^(Theta) =- 22500 kJ mol^(-1)` `2Pb +O_(2)(g) rarr 2PbO(s),DeltaG^(Theta) =- 120 kJ mol^(-1)`
• Calculate the heat of formation of ammonia from the following data: `N_(2)(g)+3H_(2)(g)to2NH_(3)(g)` The bond energies of `N-=N,H-H and N-H ` bonds are 226,104 and 92 kcal respectively.
• The bond energies of `C=C` and `C-C` at `298 K` are `590` and `331 kJ mol^(-1)`, respectively. The enthalpy of polymerisation per mole of ethaylene isA. `-70kJ`B. `-72kJ`C. `72kJ`D. `-68kJ`
• In `C_(2)H_(4)` energies of formation of `(C=C) and (C-C)` are -145 kJ/mol and -80kJ/mol respectively. What is the enthalpy change w hen ethylene polymerises to form polythene?A. `+650kJ//mol`B. `+65kJ//mol`C. `-650kJ" "mol^(-1)`D. `-65kJ" "mol^(-1)`
• For the reaction: `2H_(2)(g) +O_(2)(g) rarr 2H_(2)O(g), DeltaH =- 571 kJ` bond enegry of `(H-H) = 435 kJ` and of `(O=O) = 498 kJ`. Then, calculate the average bond enegry of `(O-H)` bond using the above data.A. 484 kJB. `-484kJ`C. `271kJ`D. `-271kJ`
• Heat of formation of `2 mol` of `NH_(3)(g)` is `= -90 kJ`, bond energies of `H-H` and `N-H` bonds are `435kJ` and `390 kJ mol^(-1)`, respectively. The value of the bond enegry of `N-=N` will beA. `-472.5kJ`B. `-945kJ`C. `472.5kJ`D. `945kJ" "mol^(-1)`