Mr(MgO) = 24 + 16 = 40
Mr(H2SO3) = 1*2 + 32 + 16*3 = 82
Mr(H2SO4) = 1*2 + 32 + 16*4 = 98
Mr(Al2O3) = 27*2 + 16*3 = 102
Mr(CO) = 12 + 16 = 28
Mr(CO2) = 12 + 16*2 = 44
Mr(MgO) = 24 + 16 = 40
Mr(H2SO3) = 1*2 + 32 + 16*3 = 82
Mr(H2SO4) = 1*2 + 32 + 16*4 = 98
Mr(Al2O3) = 27*2 + 16*3 = 102
Mr(CO) = 12 + 16 = 28
Mr(CO2) = 12 + 16*2 = 44