Heat of combustion $∆\mathrm{H}°$ for C(s), H₂(g) and CH₄(g) are -94, -68 and -213 kcal/mol. Then, $∆\mathrm{H}°$ for 

C(s) + 2H₂(g) $\to$CH₄(g) is                                                                 

1. -17 kcal/mol                         

2. -111 kcal/mol

3. -170 kcal/mol                       

4. -85 kcal/mol

Heat of the neutralization is greater than 13.7 kcal in -

1. HF & NH₄OH             

2. HCl & NaOH

3. HI & KOH                   

4. HF & NaOH

If $∆{\mathrm{H}}_{\mathrm{f}}^{°}$(C₂H₄) and $∆{\mathrm{H}}_{\mathrm{f}}^{°}$(C₂H₆) are x₁ and x₂ kcal/mol then heat of hydrogenation of C₂H₄ is :-

(1) x₁ + x₂

(2) x₁ - x₂

(3) x₂ - x₁

(4) x₁ + 2x₂

One mole of methanol when burnt in O₂ gives out 723 kJ mol^-1 of heat. If one mole of O₂ is used, what will be the amount of heat evolved?

1. 482 kJ
2. 241 kJ
3. 723 kJ               
4. 924 kJ

The heat of combustion of carbon to CO₂ is -393.5 kJ/mol. The heat released upon the

formation of 35.2 g of CO₂ from carbon and oxygen gas is

1. -315 kJ               

2. +315 kJ             

3. -630 kJ                 

4. -3.15 kJ

Enthalpy change for the reaction,

 4H(g) $\to$2H₂(g) is -869.6 kJ

The dissociation energy of H-H bond is

1. -869.6 kJ                 

2. + 434.8 kJ

3. +217.4 kJ                 

4. -434.8 kJ

The enthalpy of combustion of H₂, cyclohexene (C₆H₁₀) and cyclohexane (C₆H₁₂) are -241, -3800 and -3920 kJ per mol respectively. Heat of hydrogenation of cyclohexene is:

(a) -121 kJ per mol

(b) +121 kJ per mol

(c) +242 kJ per mol

(d) -242 kJ per mol

The heat produced in calories by the combustion of one gram of carbon is called

1. Heat of combustion of carbon

2. Heat of formation of carbon

3. Calorific value of carbon

4. Heat of production of carbon

ΔE° of combustion of isobutylene is –X kJ mol^–1. The value of ΔH° is [DCE 2004]

1. = ΔE°

2. > ΔE°

3. = 0

4. < ΔE°

The standard entropies of CO₂(g), C(s) and O₂(g) are 213.5, 5.690 and 205 JK^–1 respectively. The standard entropy of formation of CO₂(g) is

(1) 1.86 JK^–1

(2) 1.96 JK^–1

(3) 2.81 JK^–1

(4) 2.86 JK^–1