250 - 100\%
x - 20\%
100x = 5000
x = 50 г
M(NaBr) =m(раствора) *w(NaBr) ;
w (NaBr) = 15 % = 0.15
m (NaBr) = 300г *0.15 =45г
2) m (KNO3) = m (раствора) *w(KNO3)
w(KNO3) = 8 % = 0.08
m(KNO3) = 200г *0.08 =16г
3) m(CaCl2) = m (раствора) *w(CaCl2)
w (CaCl2) = 5 % = 0.05
m(CaCl2) = 400г *0.05 =20г
M(AL)=27 g/mol
M(Al2O3)=102 g/mol
W(Al)=27/102 * 100% =26.47%
2Ca + O2 = 2CaO
CaO + H2O = Ca(OH)2
Ca(OH)2 + CO2 = CaCO3 + H2O
CaCO3 (t)= CaO + CO2
CaO + 3C (t)= CaC2 + CO