When a Zn road is added to CuSO4 solution copper is deposited, but the reverse reaction does not occur why?
Answers
Mixing Zinc Metal with Solid Copper Sulphate will have NO reaction, But assuming the Copper Sulphate is in Aqueous/Molten State, The Zinc reacts with Copper Sulphate/Sulfate.
It will undergo a Redox Reaction ,called the Displacement Reaction of Metal because Zinc is More Reactive than Copper according to the Reactivity Series. It WILL NOT react if both are in Solid State , Your question has to be clearer.
But firstly it depends on what is the oxidation state of the Copper since Copper is a Transition Metal and have varying Oxidation State. There is Copper (I) and Copper (II) and even Copper (III) . Also ,the Copper Sulphate has to be in Aqueous State ,dissolved in water in order for the reaction to occur , so in order to get the Dry sample (Anhydrous Salt) , You will have to use Evaporation To Dryness , if not , Crystallisation to get the Hydrated Copper Sulphate Crystals.
So assuming you are talking about Copper(II) Sulphate , The Full Chemical equation would be as follows
Zinc + Copper (II) Sulfate → Copper Metal + Zinc Sulfate
Zn (s) + CuSO₄ (aq) → ZnSO₄ (aq) + Cu (s)
The Copper form will be the Reddish Brown deposit and the Copper II Sulphate Solution will become less blue (Paler)
The Ionic Equation is
Zn (s) + Cu²⁺ (aq) → Zn²⁺ (aq) + Cu (s)
Change in Free Energy: ΔG(20C) = -206.6kJ
Change in Enthalpy: ΔH(20C) = -208.8kJ (Exothermic Reaction)