Chemistry questions
29404 published questions with worked solutions.
- The heat produced during combustion of 7.8 g C_6H_6 at constant volume forming H_2O_ (l) and CO_ 2(g) is 40 kJ at 27 °C. The heat...
- The H_2O_ (g) molecule dissociates as (i) H_2O_ (g) H_ (g) + OH_ (g) ; H = 490 kJ (ii) OH_ (g) H_ (g) + O_ (g) ; H = 424 kJ The...
- In the combustion of 11 g of CO_ 2(g) , 100 kJ of heat is liberated. Heat of combustion of CO_ 2(g) is _________
- The heat of formations of CO_ (g) and CO_ 2(g) are -26.4 kcal and -94.0 kcal respectively. The heat of combustion of carbon...
- 2.1 g of Fe combines with S evolving 3.77 kJ. The heat of formation of FeS in kJ/mol is _________
- The heat of atomization of PH_ 3(g) is 228 kcal ,mol^ -1 and that of P_2H_ 4(g) is 355 kcal ,mol^ -1 . The energy of P-P bond is...
- Standard enthalpy of combustion at 25 °C of hydrogen, cyclohexene ( C_6H_ 10 ) and cyclohexane ( C_6H_ 12 ) are -240, -3800 and...
- Diborane is a potential rocket fuel which undergoes combustion according to the equation B_2H_ 6(g) + 3O_ 2(g) B_2O_ 3(g) +...
- When 2 moles of C_2H_ 6(g) are completely burnt, 3129 kJ of heat is liberated. If _fH for CO_ 2(g) and H_2O_ (l) are -395 and...
- Heat of formation of CO_ 2(g) , H_2O_ (l) and CH_ 4(g) are -94.0, -68.4 and -17.9 kcal respectively. The heat of combustion of...
- Given: (i) S + O_2 SO_2 , H = -298.2 kJ (ii) SO_2 + 1 2 O_2 SO_3 , H = -98.7 kJ (iii) SO_3 + H_2O H_2SO_4 , H = -130.2 kJ (iv)...
- The _fH^ of O_3 , CO_2 , NH_3 and HI are +142.2, -393.3, -46.2 and +25.9 kJ ,mol^ -1 respectively. The order of their increasing...
- The heat evolved in the combustion of benzene is given by C_6H_6 + 7 1 2 O_2 6CO_ 2(g) + 3H_2O_ (l) ; H = -3264.6 kJ. Which of...
- In the combustion of 2.0 g of methane 25 kcal heat is liberated, heat of combustion of methane would be __________
- Calculate the enthalpy of hydrogenation of C_2H_ 4(g) , given that the enthalpy of formation of ethane and ethylene as -30.2 kcal...
- The combustion enthalpies of carbon, hydrogen and methane are -395.5 kJ ,mol^ -1 , -285.8 kJ ,mol^ -1 and -890.4 kJ ,mol^ -1...
- Given: 2C_ (s) + 2O_ 2(g) 2CO_ 2(g) ; H_1 = -767 kJ ...(i) H_ 2(g) + 1 2 O_ 2(g) H_2O_ ( ) ; H_2 = -266 kJ ...(ii) C_2H_ 2(g) + 5...
- Given the bond energies N≡N, H-H and N-H bonds are 945, 436 and 391 kJ ,mole^ -1 respectively, the enthalpy of the following...
- For a reaction, H = 9.08 kJ ,mol^ -1 and S = 35.7 J ,K^ -1 ,mol^ -1 . Which of the following statements is CORRECT for the...
- For the change H_2O_ (l) H_2O_ (g) ; P = 1 atm, T = 373 K, the free energy change G = 0. This indicates that ________