If `x_(1)` , `x_(2)` and `x_(3)` are enthalpies of `H-H` , `O=O` and `O-H` bonds respective, and `x_(4)` is the enthaply of vaporisation of water, estimate the standard enthalpy opf combustion of hydrogen.

If x_(1) , x_(2) and x_(3) are enthalpies of H-H , O=O and O-H bonds respective, and x_(4) is the enthaply of vaporisation of water, estimate the standard enthalpy opf combustion of bydrogen.

What will be standard enthalpy of formation of H_(2)O(l) ?

Bond angles in H-O-O and H-O-H in H_2 O_2 and water respectively are

At 25^(@) C, is the standard reaction enthalpy for the reaction 2H(g) +O(g)toH_(2)O(l) the same as the standard enthalpy of formation of H_(2)O(l) ?

The enthalpy of vaporisation for water is 41.2 kJ mol^(-1), DeltaH for the reaction 2H_2O(g) to 2H_2O(l) is :

If bond enthalpies Of N-=N,H-Hand N-H bonds are x_(1),x_(2)and x_(3) respectively , DeltaH_(f)^(@) for NH_(3) will be :

(i) What do you mean by standard enthalpy of formation? (ii) Is the standard enthalpy of reaction of the following reaction equal to the standard enthalpy off formation of H_(2)O(l) at 25^(@)C:H_(2)(g)+(1)/(3)O_(3)(g)toH_(2)O(l) ? Explain.