1.
Balance the following chemical equations KFFeO 13- Cels+ 16 NagSos 17- Find the
Charges(Oxidation number) of the underlined elements A) Mgso Mg Pb- Fe= o-
Solution
10. 3O2(g) ---------> 2O3(g)
11. 2KF + FeO -------> FeF2 + K2O
12. P4 + 6H2 ---------> 4PH3
13.C4H8 + 6O2 ---------> 4Co2 + 4H2O
14.2KClO3 ------------> 2KCl + 3O2
15. Ca(OH)2 + H2So4 --------> CaSo4 + 2H2O
16. Na2SO3 + S ----------> Na2S2O3
17.
A.  MgSo4 --------> Mg^2+ + SO4^2-
SO4^2-
x + (-2*4) = -2
x -8Â Â = -2
x = 6
s = +6
Mg = +2
SÂ Â = +6
O = -2
B. Pb3(PO4)4 ---------> Pb^4+ + PO4^3-
PO4^3-
x + (-2*4) = -3
x-8Â Â = -3
x = +5

2.
P = +5
Pb = +4
P = +5
O = -2
C. Fe2(CO3)3 -----------> Fe^3+Â Â Â +Â Â CO3^2-
CO3^2-
x + (-2*3) = -2
x -6Â Â = -2
x = +4
CÂ Â = +4
Fe = +3
CÂ Â = +4
O = -2