An imaginary reaction `X rarr Y` takes place in three steps `X rarr A, DeltaH=-q_(1), " "BrarrA, DeltaH=-q_(2), " "BrarrY, DeltaH=-q_(3)` If Hess's law is applicable, then the heat of the reaction `(X rarr Y)` is :
H_2 + Cl_2 rarr 2HCl , DeltaH_1, N_2 + 3H_2 rarr 2NH_3, DeltaH_2 and NH_3 + 3Cl_2 rarr NCl_3 + 3HCI, DeltaH_3 . Then calculate the heat of formation of nitrogen trichloride.
2H_(2(g)) + O_(2(g)) rarr 2H_(2)O_((l)) , DeltaH= -ve and DeltaG= -ve . Then the reaction is
Given that C + O_2 rarr CO_(2) , DeltaH^@ = -xkJ 2CO + O_2 rarr 2CO_2 , DeltaH^@ = -y kJ The enthalpy of formation of carbon monoxide will be
Three charges -q_(1), + q_(2) and -q_(3) are placed as shown in the figure. The x - component of the force on q_(1) is proportional to
Chemical reactions are invariably assocated with the transfer of energy either in the form of heat or light. In the laboratory, heat changes in physical and chemical processes are measured with an instrument called calorimeter. Heat change in the process is calculated as: q= ms DeltaT , s= specific heat = c Delta T , c= heat capacity Heat of reaction at constant volume is measured using bomb calorimeter. qv= Delta U= internal energy change. Heat of reaction at constant pressure is measured using simple or water calorimeter. q_(p) = Delta H, q_(p) = q_(v) + P Delta V, DeltaH = DeltaU + Delta nRT The amount of energy released during a chemical change depnds on the physical state of reactants and products, the condition of pressure, temperature and volume at which the reaction is carried out. The variation of heat of reaction with temperature and pressure is given by Kirchhoff's equation: (DeltaH_(2)- DeltaH_(1))/(TT_(2)-T_(1)) = DeltaC_(P) (At constant pressure), (DeltaU_(2)- DeltaU_(1))/(TT_(2)-T_(1)) = DeltaC_(V) (At constant volume) DeltaC_(P) for a reaction is given by 0.2T cal/deg. Its enthalpy of reaction at 10K is -14.2 kcal. Its enthalpy of reaction at 100K in kcal will be
Chemical reactions are invariably assocated with the transfer of energy either in the form of heat or light. In the laboratory, heat changes in physical and chemical processes are measured with an instrument called calorimeter. Heat change in the process is calculated as: q= ms DeltaT , s= specific heat = c Delta T , c= heat capacity Heat of reaction at constant volume is measured using bomb calorimeter. qv= Delta U= internal energy change. Heat of reaction at constant pressure is measured using simple or water calorimeter. q_(p) = Delta H, q_(p) = q_(v) + P Delta V, DeltaH = DeltaU + Delta nRT The amount of energy released during a chemical change depnds on the physical state of reactants and products, the condition of pressure, temperature and volume at which the reaction is carried out. The variation of heat of reaction with temperature and pressure is given by Kirchhoff's equation: (DeltaH_(2)- DeltaH_(1))/(TT_(2)-T_(1)) = DeltaC_(P) (At constant pressure), (DeltaU_(2)- DeltaU_(1))/(TT_(2)-T_(1)) = DeltaC_(V) (At constant volume) The heat capacity of bomb calorimeter (with its contents) is 500J/K. When 0.1g of CH_(4) was burnt in this calorimeter the temperature rose by 2^(@)C . The value of DeltaU per mole will be
1) C_("Graphite") + O_(2(g)) rarr CO_(2(g)) , DeltaH = -94 K.Cals 2) C_("Diamond") + O_(2(g)) rarr CO_(2(g)) , DeltaH =-94.5 K.Cals From the above data the heat of transition of C_("diamond") rarr C_("Graphite")
NARENDRA AWASTHI-THERMODYNAMICS-Level 3 - Match The Column
