Question

In Experiment 2: Separation of a Heterogeneous Mixture, a redox reaction was performed. Which equation below describes that reaction. (a) CuSO4(aq) + Zn(s) → ZnSO4(aq) + Cu(s) (b) SiO2(s) + 2CuSO4 → 2Cu(s) + Si(SO4)2(aq) (c) SiO2(s) → Si(s) + O2(g) (d) Cu(s) + ZnSO4(aq) → CuSO4(aq) + Zn(s) (e) SiO2(s) + 2CuSO4(aq) → Si(SO4)2(aq) + 2CuO(s)

Answer 1

Equation ( a) describes the reaction as here Zn undergoes oxidation and gets converted to Zinc sulphate. Copper sulphate undergoes reduction & form Cu.

In Equation b even though Copper has undergone reduction from Copper Sulphate to Copper but Silicon dioxide has not undergone oxidation because its oxidation state has not changed . It has remained the same i.e +4 in silicon dioxide as well as in silicon sulphate.Same explanation is valid for equation e.

In equation C on reactant side its not heterogenous mixture, its just single compound i.e silicon dioxide

Equation d is the wrong reaction as Copper cannot displace Zinc from its solution. According to the electrochemical series we know that copper is less reactive than zinc and it lies below zinc in the activity series so the reaction doesn't takes place.

Therefore Answer is equation a