Chemistry questions
29404 published questions with worked solutions.
- The standard heat of formation of ethane, CO_2 and H_2O( l ) are -21.1, -94.1 and -68.3 kcal respectively. The standard heat of...
- In exothermic reaction the products are
- The heat of formation of Fe_2O_3(s) is -824.2 kJ ,mol^ -1 , H for the reaction 2Fe_2O_3(s) 4Fe(s)+3O_2(g) is :
- In the dissociation of CH_4(g)
- 1 mole of H_2SO_4 is mixed with 2 moles of KOH , the heat evolved will be
- The bond dissociation energies for F_2 , Cl_2 , Br_2 and I_2 are 37, 58, 46 and 36 kJ ,mole^ -1 respectively. The strongest bond...
- The enthalpy of formation for C_2H_4(g) , CO_2(g) and H_2O( l ) at 25^ C and 1 atm. pressure are 52, -394 and -286 kJ ,mol^ -1...
- Which one of the following reaction defines _fH^0?
- The enthalpy of bond dissociation of H_2(g) , Cl_2(g) and HCl(g) are 104, 58 and 103 kcal mol^ -1 respectively. The enthalpy of...
- If _fH(X), _fH(Y), _fH(R), _fH(S) denote the enthalpies of formation of X, Y, R and S respectively the enthalpy of the reaction....
- Heat of formation H^0_f of an explosive compound is
- If the heat of formation of MH_4 is -1600 kJ , the bond energy of M-H would be :
- The standard heat of formation of diamond is
- Heat evolved in the reaction H_2(g)+Cl_2(g) 2HCl(g) is 182 kJ . The bond enthalpy of H-H , Cl-Cl bond are 430, 242 kJ mol^ -1...
- The H^0_f ( kJ ,mol^ -1 ) for CO_2(g) , CO(g) , N_2O(g) and NO_2(g) are -393, -110, 81 and 34 respectively. What is the value of...
- You are given the following two reactions : 1. CH_4(g)+2O_2(g) CO_2(g)+2H_2O(g) ; [ H=-890.4 kJ ] 2. 2HgO(s) 2Hg( l )+O_2(g) ; [...
- The bond enthalpy of C-C , C=C , H-H and C-H bonds are 350, 600, 400 and 410 kJ mol^ -1 respectively. The enthalpy change for...
- The enthalpy of formation of C_2H_2(g) and C_6H_6(g) at 298 K are 230 and 85 kJ/mol respectively. The enthalpy change, H for the...
- The bond enthalpy of N N , H-H and N-H bonds are 945, 436 and 391 kJ mol^ -1 respectively, enthalpy change for reaction...
- The bond energy of H_2 is 436.4 kJ . This means that