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@@ -485,9 +485,444 @@ Se (gray) & 221 & 685 & Hexagonal & Photocells, glass \\
 
 \ce{2Ca3(PO4)2 + 6SiO2 + 10C ->[high T] 6CaSiO3 + 10CO ^ + P4 ^}
 
-\section{Acids and bases}
+\section{Acids and bases ions}
 
-\section{Ions}
+\subsection{Hydrogen halides}
+
+\subsubsection{Hydrofluoric acid}
+
+\textbf{HF} (Hydrofluoric acid, Hydrogen fluoride)
+
+\textbf{Valence:} F is -1, H is +1
+
+\textbf{Properties:} Weak acid in aqueous solution (unlike other hydrogen halides), can dissolve glass.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Etching glass: \ce{SiO2 + 4HF -> SiF4 ^ + 2H2O}
+\item With calcium: \ce{Ca + 2HF -> CaF2 + H2 ^}
+\item Formation of hexafluorosilicate: \ce{SiO2 + 6HF -> H2SiF6 + 2H2O}
+\end{itemize}
+
+\subsubsection{Hydrochloric acid}
+
+\textbf{HCl} (Hydrochloric acid, Hydrogen chloride)
+
+\textbf{Valence:} Cl is -1, H is +1
+
+\textbf{Properties:} Strong acid, colorless gas, forms white fumes in moist air.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Oxidation by manganese dioxide: \ce{MnO2 + 4HCl ->[heat] MnCl2 + Cl2 ^ + 2H2O}
+\item With ammonia: \ce{NH3 + HCl -> NH4Cl} (white smoke)
+\item Dissolving metals: \ce{Fe + 2HCl -> FeCl2 + H2 ^}
+\item With permanganate: \ce{2KMnO4 + 16HCl -> 2KCl + 2MnCl2 + 5Cl2 ^ + 8H2O}
+\end{itemize}
+
+\subsubsection{Hydrobromic acid}
+
+\textbf{HBr} (Hydrobromic acid, Hydrogen bromide)
+
+\textbf{Valence:} Br is -1, H is +1
+
+\textbf{Properties:} Strong acid, stronger reducing agent than HCl.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Oxidation by sulfuric acid: \ce{2HBr + H2SO4 -> Br2 + SO2 + 2H2O}
+\item With silver nitrate: \ce{HBr + AgNO3 -> AgBr v + HNO3} (pale yellow precipitate)
+\end{itemize}
+
+\subsubsection{Hydroiodic acid}
+
+\textbf{HI} (Hydroiodic acid, Hydrogen iodide)
+
+\textbf{Valence:} I is -1, H is +1
+
+\textbf{Properties:} Strong acid, strongest reducing agent among hydrogen halides.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Oxidation by sulfuric acid: \ce{8HI + H2SO4 -> 4I2 + H2S + 4H2O}
+\item Reduction of Fe(III): \ce{2Fe^3+ + 2I- -> 2Fe^2+ + I2}
+\item With chlorine: \ce{2HI + Cl2 -> 2HCl + I2}
+\end{itemize}
+
+\subsection{Oxyacid}
+
+\subsubsection{Nitrogen oxyacids}
+
+\textbf{HNO$_2$} (Nitrous acid)
+
+\textbf{Structure:} \chemfig{H-O-N=O}
+
+\textbf{Valence:} N is +3, O is -2, H is +1
+
+\textbf{Properties:} Weak acid, unstable, exists only in solution.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Decomposition: \ce{3HNO2 -> HNO3 + 2NO ^ + H2O}
+\item Oxidation of iodide: \ce{2HNO2 + 2HI -> I2 + 2NO ^ + 2H2O}
+\item Reduction by reducing agents: \ce{2HNO2 + 2HI -> 2NO ^ + I2 + 2H2O}
+\end{itemize}
+
+\textbf{HNO$_3$} (Nitric acid)
+
+\textbf{Structure:} \chemfig{H-O-[:30]N(=[2]O)(-[:-30]O)}
+
+\textbf{Valence:} N is +5, O is -2, H is +1
+
+\textbf{Properties:} Strong acid, strong oxidizing agent.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item With copper: \ce{3Cu + 8HNO3(dilute) -> 3Cu(NO3)2 + 2NO ^ + 4H2O}
+\item Concentrated with copper: \ce{Cu + 4HNO3(conc.) -> Cu(NO3)2 + 2NO2 ^ + 2H2O}
+\item Nitration reaction: \ce{C6H6 + HNO3 ->[H2SO4] C6H5NO2 + H2O}
+\item With phosphorus: \ce{P4 + 20HNO3 -> 4H3PO4 + 20NO2 ^ + 4H2O}
+\item Passivation of iron: \ce{Fe + 6HNO3(conc.) -> Fe^3+ (passive layer)}
+\end{itemize}
+
+\subsubsection{Sulfur oxyacids}
+
+\textbf{H$_2$SO$_3$} (Sulfurous acid)
+
+\textbf{Structure:} \chemfig{HO-[:30]S(=[2]O)(-[:-30]OH)}
+
+\textbf{Valence:} S is +4, O is -2, H is +1
+
+\textbf{Properties:} Weak acid, exists only in solution, reducing agent.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Oxidation by oxygen: \ce{2H2SO3 + O2 -> 2H2SO4}
+\item Reduction by hydrogen sulfide: \ce{H2SO3 + 2H2S -> 3S v + 3H2O}
+\item With bromine: \ce{H2SO3 + Br2 + H2O -> H2SO4 + 2HBr}
+\end{itemize}
+
+\textbf{H$_2$SO$_4$} (Sulfuric acid)
+
+\textbf{Structure:} \chemfig{HO-[:30]S(=[2]O)(=[:-30]O)(-[:90]OH)}
+
+\textbf{Valence:} S is +6, O is -2, H is +1
+
+\textbf{Properties:} Strong acid, strong dehydrating agent, strong oxidizing agent (concentrated).
+
+\textbf{Reactions:}
+\begin{itemize}
+\item With carbon (dehydration): \ce{C12H22O11 ->[H2SO4(conc.)] 12C + 11H2O}
+\item Hot concentrated with copper: \ce{Cu + 2H2SO4(conc.) ->[heat] CuSO4 + SO2 ^ + 2H2O}
+\item With NaCl (making HCl): \ce{NaCl + H2SO4 ->[heat] NaHSO4 + HCl ^}
+\item Esterification: \ce{CH3COOH + C2H5OH <=>[H2SO4] CH3COOC2H5 + H2O}
+\end{itemize}
+
+\subsubsection{Phosphorus oxyacids}
+
+\textbf{H$_3$PO$_3$} (Phosphorous acid)
+
+\textbf{Structure:} \chemfig{H-[:30]P(=[2]O)(-[:-90]OH)(-[:150]OH)}
+
+\textbf{Valence:} P is +3, O is -2, H is +1 (in OH groups), H is +1 (bonded to P)
+
+\textbf{Properties:} Dibasic acid (only 2 acidic H), reducing agent.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Reduction of silver nitrate: \ce{H3PO3 + 2AgNO3 + H2O -> H3PO4 + 2Ag v + 2HNO3}
+\item Disproportionation: \ce{4H3PO3 ->[heat] 3H3PO4 + PH3 ^}
+\end{itemize}
+
+\textbf{H$_3$PO$_4$} (Phosphoric acid)
+
+\textbf{Structure:} \chemfig{HO-[:30]P(=[2]O)(-[:-30]OH)(-[:90]OH)}
+
+\textbf{Valence:} P is +5, O is -2, H is +1
+
+\textbf{Properties:} Weak tribasic acid, non-oxidizing.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Dehydration to pyrophosphoric acid: \ce{2H3PO4 ->[heat] H4P2O7 + H2O}
+\item With ammonia: \ce{H3PO4 + NH3 -> NH4H2PO4}
+\item Esterification: \ce{H3PO4 + 3C2H5OH -> (C2H5O)3PO + 3H2O}
+\end{itemize}
+
+\subsubsection{Chlorine oxyacids}
+
+\textbf{HClO} (Hypochlorous acid)
+
+\textbf{Structure:} \chemfig{H-O-Cl}
+
+\textbf{Valence:} Cl is +1, O is -2, H is +1
+
+\textbf{Properties:} Very weak acid, strong oxidizing agent, unstable.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Disproportionation: \ce{3HClO -> HClO3 + 2HCl}
+\item Oxidation: \ce{HClO + H2S -> HCl + S v + H2O}
+\item Bleaching: \ce{HClO + [dye] -> [oxidized dye] (colorless)}
+\end{itemize}
+
+\textbf{HClO$_2$} (Chlorous acid)
+
+\textbf{Structure:} \chemfig{H-O-[:30]Cl(=[2]O)}
+
+\textbf{Valence:} Cl is +3, O is -2, H is +1
+
+\textbf{Properties:} Weak acid, unstable, exists only in solution.
+
+\textbf{HClO$_3$} (Chloric acid)
+
+\textbf{Structure:} \chemfig{H-O-[:30]Cl(=[2]O)(-[:-30]O)}
+
+\textbf{Valence:} Cl is +5, O is -2, H is +1
+
+\textbf{Properties:} Strong acid, strong oxidizing agent.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Oxidation of sulfur: \ce{3S + 6HClO3 -> 3H2SO4 + 3Cl2 ^}
+\item Decomposition: \ce{8HClO3 -> 4Cl2 ^ + 6O2 ^ + 4H2O}
+\end{itemize}
+
+\textbf{HClO$_4$} (Perchloric acid)
+
+\textbf{Structure:} \chemfig{H-O-[:30]Cl(=[2]O)(=[6]O)(-[:-30]O)}
+
+\textbf{Valence:} Cl is +7, O is -2, H is +1
+
+\textbf{Properties:} Very strong acid, strongest common acid, powerful oxidizing agent when hot/concentrated.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Oxidation of organic compounds: \ce{C6H12O6 + 24HClO4 ->[heat] 6CO2 ^ + 12Cl2 ^ + 18H2O}
+\item With metals: \ce{Mg + 2HClO4 -> Mg(ClO4)2 + H2 ^}
+\end{itemize}
+
+\subsubsection{Carbon oxyacids}
+
+\textbf{H$_2$CO$_3$} (Carbonic acid)
+
+\textbf{Structure:} \chemfig{HO-[:30]C(=[2]O)(-[:-30]OH)}
+
+\textbf{Valence:} C is +4, O is -2, H is +1
+
+\textbf{Properties:} Weak acid, unstable, exists in equilibrium with CO$_2$ and H$_2$O.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Decomposition: \ce{H2CO3 <=> CO2 ^ + H2O}
+\item With ammonia: \ce{H2CO3 + 2NH3 -> (NH4)2CO3}
+\item Formation: \ce{CO2 + H2O <=> H2CO3}
+\end{itemize}
+
+\subsubsection{Bromine and iodine oxyacids}
+
+\textbf{HBrO} (Hypobromous acid)
+
+\textbf{Structure:} \chemfig{H-O-Br}
+
+\textbf{Valence:} Br is +1, O is -2, H is +1
+
+\textbf{HBrO$_3$} (Bromic acid)
+
+\textbf{Structure:} \chemfig{H-O-[:30]Br(=[2]O)(-[:-30]O)}
+
+\textbf{Valence:} Br is +5, O is -2, H is +1
+
+\textbf{HIO$_3$} (Iodic acid)
+
+\textbf{Structure:} \chemfig{H-O-[:30]I(=[2]O)(-[:-30]O)}
+
+\textbf{Valence:} I is +5, O is -2, H is +1
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Oxidation: \ce{5HI + HIO3 -> 3I2 + 3H2O}
+\item With sulfur dioxide: \ce{HIO3 + 3H2SO3 -> HI + 3H2SO4}
+\end{itemize}
+
+\textbf{H$_5$IO$_6$} (Periodic acid)
+
+\textbf{Structure:} \chemfig{HO-[:18]I(-[:90]OH)(-[:162]OH)(-[:234]OH)(-[:-90]OH)}
+
+\textbf{Valence:} I is +7, O is -2, H is +1
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Oxidative cleavage of diols: Used to cleave vicinal diols (glycols) to aldehydes or ketones
+\end{itemize}
+
+\subsection{Bases from metal oxides}
+
+\subsubsection{Alkali metal hydroxides}
+
+\textbf{NaOH} (Sodium hydroxide, Caustic soda, Lye)
+
+\textbf{Valence:} Na is +1, O is -2, H is +1
+
+\textbf{Properties:} Strong base, deliquescent, corrosive.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item With aluminum (amphoteric): \ce{2Al + 2NaOH + 2H2O -> 2NaAlO2 + 3H2 ^}
+\item With silicon dioxide: \ce{SiO2 + 2NaOH ->[heat] Na2SiO3 + H2O}
+\item Saponification of esters: \ce{CH3COOC2H5 + NaOH -> CH3COONa + C2H5OH}
+\item With chlorine (disproportionation): \ce{Cl2 + 2NaOH -> NaCl + NaClO + H2O}
+\item With sulfur: \ce{3S + 6NaOH ->[heat] 2Na2S + Na2SO3 + 3H2O}
+\end{itemize}
+
+\textbf{KOH} (Potassium hydroxide, Caustic potash)
+
+\textbf{Valence:} K is +1, O is -2, H is +1
+
+\textbf{Properties:} Strong base, more hygroscopic than NaOH.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item With CO$_2$: \ce{2KOH + CO2 -> K2CO3 + H2O}
+\item Excess CO$_2$: \ce{K2CO3 + CO2 + H2O -> 2KHCO3}
+\item With haloalkanes (elimination): \ce{C2H5Br + KOH ->[alcohol] C2H4 ^ + KBr + H2O}
+\end{itemize}
+
+\textbf{LiOH} (Lithium hydroxide)
+
+\textbf{Valence:} Li is +1, O is -2, H is +1
+
+\textbf{Properties:} Strong base, used in CO$_2$ scrubbers.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item CO$_2$ absorption: \ce{2LiOH + CO2 -> Li2CO3 + H2O}
+\end{itemize}
+
+\subsubsection{Alkaline earth metal hydroxides}
+
+\textbf{Ca(OH)$_2$} (Calcium hydroxide, Slaked lime, Hydrated lime)
+
+\textbf{Valence:} Ca is +2, O is -2, H is +1
+
+\textbf{Properties:} Moderately strong base, sparingly soluble in water (lime water).
+
+\textbf{Reactions:}
+\begin{itemize}
+\item With CO$_2$ (limewater test): \ce{Ca(OH)2 + CO2 -> CaCO3 v + H2O}
+\item Excess CO$_2$: \ce{CaCO3 + CO2 + H2O -> Ca(HCO3)2} (soluble)
+\item With chlorine: \ce{2Ca(OH)2 + 2Cl2 -> CaCl2 + Ca(ClO)2 + 2H2O}
+\item Preparation from quicklime: \ce{CaO + H2O -> Ca(OH)2} (exothermic)
+\end{itemize}
+
+\textbf{Mg(OH)$_2$} (Magnesium hydroxide, Milk of magnesia)
+
+\textbf{Valence:} Mg is +2, O is -2, H is +1
+
+\textbf{Properties:} Weak base, very sparingly soluble, antacid.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Decomposition: \ce{Mg(OH)2 ->[heat] MgO + H2O}
+\item With acids (antacid action): \ce{Mg(OH)2 + 2HCl -> MgCl2 + 2H2O}
+\end{itemize}
+
+\textbf{Ba(OH)$_2$} (Barium hydroxide)
+
+\textbf{Valence:} Ba is +2, O is -2, H is +1
+
+\textbf{Properties:} Strong base, more soluble than Ca(OH)$_2$.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item With sulfuric acid: \ce{Ba(OH)2 + H2SO4 -> BaSO4 v + 2H2O}
+\item With ammonium salts (endothermic): \ce{Ba(OH)2.8H2O + 2NH4Cl -> BaCl2 + 2NH3 ^ + 10H2O}
+\end{itemize}
+
+\subsubsection{Ammonia and related bases}
+
+\textbf{NH$_3$} (Ammonia)
+
+\textbf{Structure:} \chemfig{N(-[:90]H)(-[:210]H)(-[:330]H)}
+
+\textbf{Valence:} N is -3, H is +1
+
+\textbf{Properties:} Weak base, pungent gas, very soluble in water.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Complex formation with Cu$^{2+}$: \ce{Cu^2+ + 4NH3 -> [Cu(NH3)4]^2+} (deep blue)
+\item With HCl: \ce{NH3 + HCl -> NH4Cl} (white smoke)
+\item Haber process: \ce{N2 + 3H2 <=>[Fe catalyst][high T, P] 2NH3}
+\item Oxidation by oxygen: \ce{4NH3 + 5O2 ->[Pt catalyst] 4NO + 6H2O} (Ostwald process)
+\item With chlorine: \ce{2NH3 + 3Cl2 -> N2 + 6HCl}
+\item Reduction of CuO: \ce{3CuO + 2NH3 ->[heat] 3Cu + N2 + 3H2O}
+\end{itemize}
+
+\textbf{NH$_4$OH} (Ammonium hydroxide)
+
+\textbf{Formula:} NH$_4^+$ and OH$^-$ ions in aqueous solution
+
+\textbf{Valence:} N is -3, H is +1, O is -2
+
+\textbf{Properties:} Aqueous ammonia solution, weak base.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Precipitation of metal hydroxides: \ce{Fe^3+ + 3NH4OH -> Fe(OH)3 v + 3NH4+}
+\item With excess ammonia (complex formation): \ce{Zn(OH)2 + 4NH3 -> [Zn(NH3)4]^2+ + 2OH-}
+\end{itemize}
+
+\subsubsection{Transition metal hydroxides}
+
+\textbf{Fe(OH)$_2$} (Iron(II) hydroxide, Ferrous hydroxide)
+
+\textbf{Valence:} Fe is +2, O is -2, H is +1
+
+\textbf{Properties:} Weak base, white-green solid, easily oxidized.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Oxidation: \ce{4Fe(OH)2 + O2 + 2H2O -> 4Fe(OH)3} (turns brown)
+\item Decomposition: \ce{Fe(OH)2 ->[heat] FeO + H2O}
+\end{itemize}
+
+\textbf{Fe(OH)$_3$} (Iron(III) hydroxide, Ferric hydroxide)
+
+\textbf{Valence:} Fe is +3, O is -2, H is +1
+
+\textbf{Properties:} Very weak base, brown precipitate.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Decomposition: \ce{2Fe(OH)3 ->[heat] Fe2O3 + 3H2O}
+\end{itemize}
+
+\textbf{Al(OH)$_3$} (Aluminum hydroxide)
+
+\textbf{Valence:} Al is +3, O is -2, H is +1
+
+\textbf{Properties:} Amphoteric, white precipitate, antacid.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item With acid: \ce{Al(OH)3 + 3HCl -> AlCl3 + 3H2O}
+\item With base: \ce{Al(OH)3 + NaOH -> NaAlO2 + 2H2O}
+\item Decomposition: \ce{2Al(OH)3 ->[heat] Al2O3 + 3H2O}
+\end{itemize}
+
+\textbf{Cu(OH)$_2$} (Copper(II) hydroxide, Cupric hydroxide)
+
+\textbf{Valence:} Cu is +2, O is -2, H is +1
+
+\textbf{Properties:} Weak base, blue precipitate.
+
+\textbf{Reactions:}
+\begin{itemize}
+\item Decomposition: \ce{Cu(OH)2 ->[heat] CuO + H2O}
+\item With ammonia: \ce{Cu(OH)2 + 4NH3 -> [Cu(NH3)4]^2+ + 2OH-} (deep blue solution)
+\item With tartaric acid (Fehling's reagent): Forms copper tartrate complex
+\end{itemize}
 
 \section{Ores and alloys}