Guest

1. Calculate the C ¾ H bond energy in methane at 25°C from the data. Heat of formation of methane is -17.9 kcal, heat of vaporization of carbon is 171.1 cal and heat of formation of hydrogen atoms is 52.1 kcal/mol. 2. The heats of combustion of hydrogen, ethane and ethylene are 68.4, 370.4 and 393.5 kcal per molecule respectively. Calculate the energy when ethylene is reduce to ethane. 3. The molar heat of formation of NH 4 NO­ 3 is 367.54 KJ and those of N 2 O(g) and H 2 O are 81.46 KJ and -285.78 KJ, respectively at 25°C and 1.0 atm pressure. Calculate Δ H and Δ E for the reaction. NH 4 NO 3 (s) ———> N 2 O (g) + 2H 2 O(l) 4. Given that N 2 (g) + l 2 (g) ———> 2Hl(g) ΔH = –12.46 kcal l 2 (g) ———> 2l(g) ΔH = 35.8 kcal H 2 (g) ———> 2H(g) ΔH = 103.7 kcal Calculate the bond energy of H – I 5. Calculate the maximum work done when pressure on 10 g of hydrogen is reduced from 20 to 1 atm at a constant temperature of 273 K. The gas behaves ideally. Calculate Q. 6. Standard heat of formation of HgO(s) at 298 K and at constant pressure is -90.8 kJ / mole. Excess of HgO(s) absorbs 41.84 kJ of heat at constant volume, calculate the amount of Hg that can be obtained at constant volume and 298 K, Atomic weight of Hg = 200. 7. Calculate the heat of formation of anhydrous Al 2 Cl 6 from 2Al(s) + 6HCl (aq) ——> Al 2 Cl 6 (aq) + 3H 2 (g), ΔH = –239.76 kcal H 2 (g) + Cl 2 ——> 2HCl(g) ΔH = –44.0 kcal HCl(g) + Aq ——> HCl(aq.) ΔH = –17.32 kcal Al 2 Cl 6 (s) + Aq ——> Al 2 Cl 6 (aq.) ΔH = –153.69 kcal 8. Calculate the heat of formation of Ag 2 O from following data: 9. Calculate resonance energy of from the following data if the observed heat of formation of is -439.7 kJ. Bond Energy Heat of atomisation (kJ) C – H = 413 C = 716.7 C – C = 348 H = 218.0 C = O = 732 O = 249.1 C – O = 351 O – H = 463 10. For a reaction, ΔH = 30 KJ mol - 1 and Δ S = 0.07 KJ K - 1 mol - 1 at 1 atm. Calculate upto which temperature, the reaction would not be spontaneous.


1.   Calculate the C ¾ H bond energy in methane at 25°C from the data. Heat of formation of methane is -17.9 kcal, heat of vaporization of carbon is 171.1 cal and heat of formation of hydrogen atoms is 52.1 kcal/mol.


 

 


 

2.   The heats of combustion of hydrogen, ethane and ethylene are 68.4, 370.4 and 393.5 kcal per molecule respectively. Calculate the energy when ethylene is reduce to ethane.


 

 


 

3.   The molar heat of formation of NH4NO­3 is 367.54 KJ and those of N2O(g) and H2O are 81.46 KJ and -285.78 KJ, respectively at 25°C and 1.0 atm pressure. Calculate ΔH and ΔE for the reaction.


 


 


         NH4NO3(s) ———> N2O (g) + 2H2O(l)

 


4.   Given that                                                           


 

      N2(g) + l2 (g) ———> 2Hl(g)           ΔH = –12.46 kcal


 

      l2(g)  ———> 2l(g)                        ΔH = 35.8 kcal


 


      H2(g) ———> 2H(g)                       ΔH = 103.7 kcal


    



      Calculate the bond energy of H – I


 

5.   Calculate the maximum work done when pressure on 10 g of hydrogen is reduced from 20 to 1 atm at a constant temperature of 273 K. The gas behaves ideally. Calculate Q.


 

6.   Standard heat of formation of HgO(s) at 298 K and at constant pressure is -90.8 kJ / mole. Excess of HgO(s) absorbs 41.84 kJ of heat at constant volume, calculate the amount of Hg that can be obtained at constant volume and 298 K, Atomic weight of Hg = 200.


 

7.   Calculate the heat of formation of anhydrous Al2Cl6 from


 

      2Al(s) + 6HCl (aq) ——> Al2Cl6(aq) + 3H2(g),               ΔH = –239.76 kcal


 

      H2(g) + Cl2  ——> 2HCl(g)                                          ΔH = –44.0 kcal


 

      HCl(g) + Aq  ——> HCl(aq.)                                       ΔH = –17.32 kcal


 

      Al2Cl6(s) + Aq  ——> Al2Cl6(aq.)                               ΔH = –153.69 kcal


 

8.   Calculate the heat of formation of Ag2O from following data:


 

2164_equation.JPG


 


9.   Calculate resonance energy of from the following data if the observed heat of formation of is -439.7 kJ.


 

      Bond Energy                             Heat of atomisation (kJ)


 

      C – H = 413                                        C = 716.7


 

      C – C = 348                                        H = 218.0


 

      C = O = 732                                       O = 249.1


 

      C – O = 351        


 

      O – H = 463        


  

10.For a reaction, ΔH = 30 KJ mol-1 and ΔS = 0.07 KJ K-1 mol-1 at 1 atm. Calculate upto which temperature, the reaction would not be spontaneous.


 

Grade:

0 Answers

No Answer Yet!

ASK QUESTION

Get your questions answered by the expert for free