1-б
2-г
3-в
4-в
5-г
6-а
7-г
8-253
9-2Mg+O2=2MgO
MgO+2HCl=MgCl2+H2O
MgCl2+2NaOH=2NaCl+Mg(OH)2
Mg(OH)2=MgO+H2O
-------------------------
C+O2=CO2
CO2+2NaOH=Na2CO3+H2O
Na2CO3+H2SO4=Na2SO4+CO2+H2O
Na2SO4+BaCl2=BaSO4+2NaCl
--------------------------
10. BaO+H2SO4=BaSO4+H2O
n(BaO)=m:M=30,6:153=0,2(моль)
n(BaSO4)=n(BaO)=0.2(моль)
m(BaSO4)=n*M=0.2*233=46,6(г)