<span> а)Ca-->CaO-->Ca(OH)2--->Ca(NO3)2--->CaSO4</span>
<span>1) 2Ca + O2---> 2CaO</span>
<span>2) CaO + H2O---> Ca(OH)2</span>
<span>3) Ca(OH)2 + 2HNO----> Ca(NO)3 +2H2O</span>
<span>4) Ca(NO)3 + H2SO4---> CaSO4 + 2HNO3</span>
<span>
</span>
<span><span>б)Al2O3-->AL2(SO4)3--->AL(OH)3-->AL2O3</span></span>
<span><span>1) Al2O3+ 3 H2SO4---> Al2(SO4)3 + 3H2O</span></span>
<span><span>2) Al2(SO4)3 + 6NaOH---> 2Al(OH)3 + 3Na2SO4</span></span>
<span><span>3)2Al(OH)3 ---> Al2O3 + 3H2O</span></span>
<span><span>
</span></span>
<span><span><span>в)Cu---CuCl2--->Cu(OH)2--->CuO-->cU--->CuSO4--->Cu(OH2)</span></span></span>
<span><span><span>1) Cu + 2HCl---> CuCl2 + H2</span></span></span>
<span><span><span>2) CuCl2 + 2NaOH---> Cu(OH)2 + 2NaCl</span></span></span>
<span><span><span>3) Cu(OH)2---> CuO + H2O</span></span></span>
<span><span><span>4)Cu + 2H2SO4--->CuSO4 + SO2 + 2H2O</span></span></span>
<span><span><span>5) CuSO4 + 2NaOH---> Cu(OH)2+ Na2SO4</span></span></span>