Write a chemical equation for iron metalcombining with chlorine gas to produce ferrouschloride solid.

Describe the electrolytic process for refining copper.

(a) Write equations for the half-reactions that occur at the cathode and the anode when an aqueous solution of KCl is electrolyzed. Which chemical species is oxidized, and which chemical species is reduced in this reaction? (b) Predict the products formed when an aqueous solution of CsI is electrolyzed.

Three reactions very important to the semiconductor industry are The reduction of silicon dioxide to crude silicon, SiO2(s) + 2 C(s) → Si(s) + 2 CO(g) ΔrH° = 689.9 kJ/mol The formation of silicon tetrachloride from crude silicon, Si(s) + 2 Cl2(g) → SiCl4(g) ΔrH° = −657.01 kJ/mol The reduction of silicon tetrachloride to pure silicon with magnesium, SiCl4(g) + 2 Mg(s) → 2 MgCl2(s) + Si(s) ΔrH° = −625.6 kJ/mol Calculate the overall enthalpy change when 1.00 mol sand, SiO2, changes into very pure silicon by this series of reactions.