C
AlCl3 + NaOH ----> Na2SO4 + Al(OH)3 ......................................................
$Al__2O_3+H_2SO_4--------------->Al_2(SO_4)_3+H_2O$
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H2O + Na2O -> 2NaOH
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NaCl+AgNO3================================>AgCl+NaNO3
$4Ag+O_2--t^0-->2Ag_2O$ .
$2Ag+O3---->Ag_2O +O_2$ .
$H2O+CaO---->Ca(OH)2$ .
$CaO+H_2O-------->Ca(OH)_2$
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