11. Conservation of Mass, Charge, and       Energy   Previous PageNext Page
      PROBLEMS
5. Write the oxidation number for each atom in:

(a) topaz, Al2SiO4F2 (f) quartz, SiO2
(b) lead sulfide, PbS (g) garnet, Ca3Al2Si3O12
(c) sulfur, S8 (h) hydrogen fluoride, HF
(d) borax, Na2B4O7.10H2O (i) lithium hydride, LiH
(e) ammonium nitrate, NH4NO2 (j) oxygen difluoride, OF2

6. Balance the following chemical equations properly by the oxidation-number method. What substance is oxidised and which is reduced in each example?

(a) MnO2 + Cl Mn2 + Cl2 (acidic solution)
(b) NaCl + SO3 Cl2 + SO2 + Na2S2O7
(c) KBrO3 + KI + H2SO4 KBr + K2SO4 + I2
(d) Sb2S3 + HNO3 Sb2O5 + H2SO4 + NO2
(e) KI + H2SO4 K2SO4 + SO2
(f) Na2CrO2 + NaClO + NaOH Na2CrO4 + NaCl
(g) N2O4 + BrO3 NO3 + Br (acidic solution)
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