![](https://cos-cdn.shuashuati.com/pipixue-web/2020-1231-2005-12/ti_inject-812ce.png)
Which of the enthalpy changes of the following reactions can only be obtained by application of Hess’ Law? 1The hydration of anhydrous copper sulphate to form crystals of CuSO4.5H2O. 2 The formation of methane from its elements. 3.The combustion of glucose, C6H12O6.