用化学方程式表示除去下列各物质中杂质的原理(括号内的物质为杂质)1{5x+b0C5v.G-K;v+i5\/f)h
(1)KCl(KClO3)2KCl+3O2↑ ">(_-L+v7y4^ 。1{5x+b0C5v.G-K;v+i5\/f)h
(2)N2(O2)2CuO">7s*w/K(u7m8^8^5j+Q1} 。1{5x+b0C5v.G-K;v+i5\/f)h
(3)金属铜(金属锌)1a,L(W.s:t7y+o5n'?*d5g.I(V1j-q(w 。1{5x+b0C5v.G-K;v+i5\/f)h