1. найдем массу <span>MgSO4 =120* 24,6/246 = 12 г
2. W=12/(24,6+55,4)=0,15=15%</span>
А) CaO+N2O5--->Ca(NO3)2+NO2
Б) SO3+CuO--->CuSO3+O2
Г)Fe2O3+SiO2--->FeSiO3
1)CH3-CH(NH2)-COOH<span> + </span>NaOH<span> →</span> CH3-CH(NH2)-COONa + H2O
2) СH3-CH2-CH(NH2)-COOH + HCl = CH3-CH2-CH(NH3Cl)-COOH
2H2S + 3O2 = 2SO2 + 2H2O
2SO2 + O2 = 2SO3
SO3 + Na2O = Na2SO4