Знебарвлення відбувається при додаванні у речовину індикатора(фенол-фталеїн, лакмус, метил-оранж)
а-2
Ca +2 NaOH=Ca(OH)2+2Na
<span>Ca + 2H2O=Ca(OH)2 +H2</span>
<span>2Ca+O2=2CaOб</span>
б-3
<span><span>KOH +NH4Cl=KCl+NH3+H2O</span></span>
<span><span><span>6KOH +P2O5=2K3PO4+3H2O</span></span></span>
<span><span><span><span>2KOH +CrO3=<span>K2CrO3+Н2O</span></span></span></span></span>
<span><span><span><span><span>в-2</span></span></span></span></span>
<span><span><span><span><span><span>SO2 +2NaOH=Na2SO3+H2O</span></span></span></span></span></span>
<span><span><span><span><span><span><span>SO2 +H2O=H2SO3</span></span></span></span></span></span></span>
<span>SO2 +O2=2SO3</span>
<span>г-5</span>
<span><span><span> ZnS + O2 = Zn+SO2</span></span></span>
<span><span><span><span> ZnS +2HСl=ZnСl2+H2S(газ)</span></span></span></span>
<span><span><span><span><span> ZnS + 2HNO3=Zn(NO3)2+H2S(газ)</span></span></span></span></span>
15) 4623
16) 2HCI+Zn= ZnCI2+H2
2NaOH+H2SO4=NA2SO4+2H2O
17) FE+2HCI=FECI2+H2
FECI2+2NAOH=FE(OH)2+2NACI
FE(OH)2=FEO+H2O
S^t=m(р.в-ва)/m(р-ра)•100г
S^20=58,8/200•100=29,4
Ответ: 29,4г
<em>Приветствую</em>
₁ ₂ ₃
P → P₂O₅ → H₃PO₄ → Ba₃(PO₄)₂
1. 4P + 5O₂ = 2P₂O₅
2. P₂O₅ + 3H₂O = 2H₃PO₄
<span>3. 2H</span>₃<span>PO</span>₄<span> + 3BaO = Ba</span>₃<span>(PO</span>₄<span>)</span>₂<span> + 3H</span>₂<span>O</span>