The enthalpy of adsorption of chemisorption is nearly
(A) `20-40kJ:mol^(-1)`
(B) `40-100kJ mol ^(-1)`
(C)` 40-200kJmol ^(-1)`
(D)` 80-240kJmol ^(-1)`

Using the bond enthalpy data given below, calculate the enthalpy of formation of acetone (g). Bond enegry C-H = 413.4 kJ mol^(-1) , Bond enegry C-C = 347.0 kJ mol^(-1) , Bond enegry C=O = 728.0 kJ mol^(-1) , Bond enegry O=O = 495.0 kJ mol^(-1) , Bond enegry H-H = 435.8 kJ mol^(-1) , Delta_("sub")H^(Theta)C(s) = 718.4 kJ mol^(-1)

Calculate the enthalpy of formation of water, given that the bond energies of H-H, O=O and O-H bond are 433 kJ mol^(-1), 492 kJ mol^(-1) , and 464 kJ mol^(-1) , respectively.

The enthalpy of combustion of methane, graphite and dihydrogen at 298 K are, -890.3 kJ mol^(-1) -393.5 kJ mol^(-1) , and -285.8 kJ mol^(-1) respectively. Enthapy of formation of CH_(4)(g) will be

Following are the values of E_(a) and DeltaH for three reactions carried out at the same temperature : I :E_(a)=20kJ mol^(-1),DeltaH=-60kJmol^(-1) II :E_(a)=10kJ mol^(-1),DeltaH=-20kJ mol^(-1) III : E_(a)=40 kJ mol^(-1),DeltaH=+15kJ mol^(-1) If all the three reaction have same frequency factor then fastest and slowest reaction are :

The standard enthalpies fo formation of CO_(2) (g), H_(2) O (1) , and glucose (s) at 25^(@)C are - 400 kJ mol^(-1), - 300 kJ mol^(-) , and - 1300 kJ mol^(-1) , respectively. The standard enthalply of combustion per gram of glucose at 25^(@)C is

The combustion enthalpies of carbon, hydrogen and ethyne are -393.5 kJ mol^(-1), - 285.8 kJ mol^(-1) and -1309.5 kJ mol^(-1) respectively at 25^(@)C . The value of standard enthalpy of formation of acetylene at this temperature is

The enthalpy of hydrogenation of but -1- ene is 125.8 kJ mol^(-1) but that of but -2- ene is nearly 120.0 kJ mol^(-1) . How will justify ?

The enthalpy and entropy change for the reaction Br_(2)(l) + Cl_(2)(g) rightarrow 2BrCl(g) are 40 kJ mol^(-1) and 110 JK^(-1) mol ^(-1) repectively. The temperature at which the reaction will be in equilibrium is

Calculated the Gibbs energy change on dissolving one mole of sodium chloride at 25^(@)C . Lattice =+ 777.0 kJ mol^(-1) Hydration of NaCI =- 774.0 kJ mol^(-1) DeltaS at 25^(@)C = 40 J K^(-1) mol^(-1)

The enthalpy of neutralisation of a strong acid by a strong base is -57.32 kJ mol^(-1) . The enthalpy of formation of water is -285.84 kJ mol^(-1) . The enthalpy of formation of hydroxyl ion is