1. Zn+H2SO4(разбав.)=ZnSO4+H2
2. ZnSO4+NaOH=Na2SO4+Zn(OH)2
<span>3.Zn(OH)2=ZnO+H2O</span>
<span>2Ca + O2 = 2CaO
</span><span>CaO + 2HCl = CaCl2 + H2O
</span><span>CaCl2 + 2NaOH = Ca(OH)2 + 2NaCl
</span><span>Ca(OH)2 + H2SO4 = CaSO4 + 2H2O</span>
10 % = 0,1
100 * 0,1 = 10 ( г ) меди
100 - 10 = 90 ( г ) цинка