<em><span>1. S: 1s² 2s² 2p⁶ 3s² 3p⁴</span></em>
<em><span><span>С: 1s² 2s² 2p²</span></span></em>
<em><span><span>S{min} = сульфиды, степень [-2];</span></span></em>
<em><span><span>S{max} = сульфаты, степень [+6];</span></span></em>
<em><span><span>C{min} = углекислый газ, степень [-4];
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<em><span><span>C{max} = карбонаты, степень [+4].
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<em><span><span>2. Fe ⇒ FeCl₂ ⇒ Fe(OH)₂ ⇒ FeO ⇒ Fe.</span></span></em>
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<em><span><span>Fe + Cl₂ = <u>FeCl₂</u>;</span></span></em>
<em><span><span>FeCl₂ + 2NaOH = 2NaCl + <u>Fe(OH)₂</u>;</span></span></em>
<em><span><span><span><span>Fe(OH)₂ ={+t°} <u>FeO</u> + H₂O;</span></span></span></span></em>
<em><span><span><span><span><span><span><span><span>FeO</span></span></span></span> + H₂ = <u>Fe</u> + H₂O.
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<em><span><span>3. H₂SO₄+2NaOH=Na₂SO₄+2H₂O;</span></span></em>
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<em><span><span>n(<span><span>H₂SO₄</span></span>)=24,5/98=0,25 моль;</span></span></em>
<em><span><span>n(NaOH)=0,25*2=0,5 моль;</span></span></em>
<em><span><span>m(<span><span>NaOH</span></span>)=n*Mr=0,5*40=20г.</span></span></em>
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<span><span><em><u>Ответ: 20г.</u></em>
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