Question

A) Balance the following equations:

i) PbCl2 + AgNO3 <----> AgCl + Pb (NO3) 2
ii) AlCl3 + NH4OH <----> Al(OH)3 + NH4Cl
iii) FeCl3 + Ca(OH)2 <----> CaCl2 + Fe(OH)3
iv) Pb(ClO3)2 + K2SO4 <----> PbSO4 + KClO3
v) Na + HOH <----> NaOH + H2
vi) Zn + HCl <----> ZnCl2 + H2
vii) Al + AgCH3COO <----> Al(CH3COO)3 + Ag
viii) MgO + HNO3 <----> Mg (NO3)2 + H2O
ix) MnO2 <----> Mn3O4 + O2
b) Why is it incorrect to alter the chemical formula when balancing an equation?

Answer 1

A-
i)
`PbCl_2 + 2AgNO_3 = 2AgCl + Pb(NO_3)2`
ii)
`AlCl_3 + 3NH_4OH = Al(OH)_3 + 3NH_4Cl`
iii)
`2FeCl_3 + 3Ca(OH)_2 = 3CaCl_2 + 2Fe(OH)_3`
iv)
`Pb(ClO_3)_2 + K_2SO_4 = PbSO_4 + 2KClO_3`
v)
`2Na + 2HOH = 2NaOH + H_2`
vi)
`Zn + 2HCl = ZnCl_2 + H_2`
vii)
`Al + 3AgCH_3COO = Al(CH_3COO)_3 + 3Ag`
viii)
`MgO + 2HNO_3 = Mg(NO_3)_2 + H_2O`
ix)
`3MnO_2 = Mn_3O_4 + O_2`

B- Because chemical formula has its own unique set of elements and subscripts

Hope this Helps :)