Which statement is true for most chemical reactions?
An energy change occurs during the breaking and forming of bonds.
The internal energy of the system increases during a reaction.
Energy is released during the formation of reactants.
The enthalpy of the products is higher than the enthalpy of the reactants.

Sorry i dont understand the question can you rephase it?

Electron equations of the given changes are as follow,a)                              cu      →      cu⁺²  + 2e⁻b)                              mg⁺²  +  2 e⁻      →      mgc)                              cl⁻    →      cl  +  1e⁻d)                              s  +  2 e⁻    →      s²⁻e)                                o²⁻      →      o  +  2 e⁻f)                              p  +  3 e⁻    →      p³⁻g)                              fe²⁺    →      fe³⁺  + 1 e⁻h)                              s²⁻    →      s⁴⁺  +  6 e⁻

The answer would be 25.3