2. Complete the reactions SiO2 + Al SICI41) + H2O(0) -- PbO2 + 4HCl(aq) - SnCl2(aq) + HgCl2(aq) SnCl2(aq) + 2HgCl2(aq) Sn2+(aq) + PbO2(s) - CaC,(s)+2 H2O(1)> Be,C(s)+4 H,O(1) 2 KC,(s)+ 2 H2O(g) SiO2(s) + C(s) - 3. Which type of carbides are these compounds? (A. Ionic, B. Metallic, C. Molecular, D. Metalloid) KC8, CaC2, K3C60, BeC2, TIC, SIC, CO2 4. Lead(IV) oxide is a good oxidizing agent. Write a chemical equation about following reactions: From Fe2+ to Fe3+ (a) PbO, +2Fe +4H* Pb? +2Fe +2H,0 From Mn2+ to MnO4- (b)SPb0, +2Mn +48 +5Pb2" +2MnO; +2H2O Exercises 5. Tin(II) ion is a good reducing agent. Write a chemical equation about following reactions: (a) From Fe2+ to Fe3+ (a) Sn? +2Fe + Sn+ +2Fe? (b) From Cu2+ to Cu (b)Sn +Cu? Sn" +Cu X X 6. Provide the reactions for the recovery of Si, Ge from their ores. SiO2 (s)+2 C(s) Si(s)+2 CO(g) GeS2+3 02 - Ge02 +2 SO2 GeO2 + 2 H2 Ge + 2 H2O 7. True of False BN A1203 Graphite Diamond Electron conductor V Heat conductor 8. Which statement is incorrect? A. Graphite is a layered structure B. Diamond is very hard C. Lead ions are toxic D. Silicon is a metal 9. Potassium is inserted between graphite layers with a structure shown in the figure. What is the atomic ratio of C and K here? 2