M(Ca(H2PO4)2 = 40 + 1*4 + 31*2 + 16*8 = 234
W(Ca) = Ar(Ca) * n / Mr(Ca(H2PO4)2) *100% = 40 *1 / 234 *100% =17%
W(H) = Ar(H) *n / Mr(Ca(H2PO4)2 *100% = 1 * 4 / 234 *100% = 1,7%
W(P) = Ar(P) * n / Mr(Ca(H2PO4)2 *100% = 31 *2 / 234 *100% = 26,5%
W(O) = Ar(O) *n / Mr(Ca(H2PO4)2 *100% = 16 * 8 / 234 *100% = 55%
1)Выписать и назвать из перечисленных веществ только соли: K2SO4, Al(OH)3, HNO3, Fe(SO4)3, AgNO3, CuS, HCl, MgO, Na2CO3, CaCl2,
Сергей03091980
K2SO4; Fe(SO4)3; AgNO3; CuS; Na2CO3; CaCl2; BaSO3; LiNO2; Ca3(PO4)2
1)Sn(+2) -2e-->Sn(+4) ок-е
2)Сu(0) -2e--->Cu(+2) ок-е
<span>Cu2S + HNO3 = Cu(NO3)2 + SO2 + NO +H2O.</span>
<span>2</span><span>HNO</span>3<span> => 2</span><span>NO</span><span> + </span><span>H</span>2<span>O</span><span> + 3</span><span><u>O</u></span>
<span /><span>Cu</span>2<span>S</span><span>=> 2</span><span>Cu</span><span>(</span><span>NO</span>3<span>)</span>2<span> + </span><span>H</span>2<span>SO</span>4
<span>Cu</span>2<span>S</span><span> + 4</span><span>HNO</span>3<span> => 2</span><span>Cu</span><span>(</span><span>NO</span>3<span>)</span>2<span> + </span><span>H</span>2<span>SO</span>4
<span>5</span><span><u>O</u></span><span> + Cu</span><span>2</span><span>S + 4HNO</span><span>3</span><span> => 2Cu(NO</span><span>3</span><span>)</span><span>2</span><span> + H</span><span>2</span><span>SO</span><span>4</span><span> + H</span><span>2</span><span>O</span>
<span>3<span>Cu</span>2<span>S</span> + 22<span>HNO</span>3 => 6<span>Cu</span>(<span>NO</span>3)2 + 3<span>H</span>2<span>SO</span>4 + 10<span>NO</span> + 8<span>H</span>2<span>O</span></span>
<span><span><span>1) сульфит натрия Na2SO3 - восстановитель.</span></span></span>
<span><span><span>2) сульфид меди Cu2S - восстановитель.</span></span></span>
<span><span><span>3) <span>Нитрат меди(II) Cu(NO3)2</span> - окислитель.</span></span></span>
<span><span><span>4) Оксид азота(<span>II)</span></span></span></span><span> NO - окислитель.</span>
<span>5) Вода H2o - восстановитель.</span>
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