metal ion
Some enzymes do not contain metals in their molecules, but need metal ions to activate them. Metal ions are enzymatic Cofactor or activator , metal ions pass through their own Valence To transfer electrons and complete the Redox reaction Metal ions are also needed to maintain the balance of water and electrolyte in organisms. In solution or melt Cations ionized out under H + It is acid, such as HCl, H two SO four ,HNO three ,H three PO four wait; Anions ionized in solution or molten state are all OH - Only alkali, such as Ca (OH) two , KOH , NaOH ，NH three ·H two O (Because NH three ·H two The ionization of O in water can represent NH three ·H two O → NH+4+OH -, so NH three ·H two O also belongs to alkali) and so on;
from Acid radical ion And metal ions or Ammonium radical The substance synthesized by ion bonding is salt, and the acid radical ion is the anion ionized by acid, such as Cl - ，SO4 2- ，NO 3- ，PO four 3- Etc; Metal ions or ammonium ions are cations ionized by alkali, such as Na + ，K + ，NH 4+ Etc; Salt has NaCl ，K two SO four wait 2. Alkali composition - metal ions+ Hydroxyl ion 3. Composition of salt - metal ion+acid radical ion
4、 Metathesis reaction ——The reaction in which two compounds exchange components with each other to form two other compounds is called metathesis reaction. AB+CD=AD+CB 5. Dilution concentrated sulfuric acid The method is to slowly inject the concentrated sulfuric acid into the water along the wall of the device and stir it continuously to make the generated heat diffuse rapidly. Do not pour water into the concentrated sulfuric acid. 6、 Neutralization reaction ——The reaction between acid and base to form salt and water is called neutralization reaction. Formula of valence of common elements and atomic groups
(Positive) Potassium sodium silver monohydrogen, dicalcium magnesium barium zinc, tri aluminum, tetrasilicon, pentanitrophosphorus.
（ Negative valence ）Negative univalent: fluorine, chlorine, bromine, iodine; Negative divalence: oxygen and sulfur.
(Variable positive value): one or two copper mercury, two or three iron, two or four carbon, and four or six sulfur.
Negative price: Hydroxyl radical （OH - ）， Nitrate （NO three - ）， Chlorate （ClO three - ）， Permanganate （MnO four -）； Negative bivalence: Sulfate radical （SO four 2- ）， Carbonate （CO three 2- ）， Sulfite （SO three 2- ）， Manganic acid Root (MnO four 2- ）； Negative triple price: Phosphate radical （PO four 3- ）； Positive price: Ammonium radical （NH four + ）。 （1） Properties of acids (1) and indicator reaction Purple litmus test solution Turn red, colorless Phenolphthalein test solution No discoloration. (2) Acid+alkali=salt+water.
(3) Acid+some metallic oxide =Salt+water. (4) Acid+active metal=salt+hydrogen.
(5) Acid+salt=new salt+ Neoacid 。 1. Zinc heel Dilute hydrochloric acid Reaction: Zn+2HCl=ZnCl two +H two ↑ Bubbles are generated, and zinc particles gradually decrease. 2、 zinc Follow Dilute sulfuric acid reaction ：Zn+H two SO four =ZnSO four +H two ↑ 3. Iron reacts with dilute hydrochloric acid: Fe+2HCl=FeCl two +H two ↑ Bubbles are generated, and iron gradually decreases,
4、 iron React with dilute sulfuric acid: Fe+H two SO four =FeSO four +H two ↑ The solution turns light green. 5. Rust heel Dilute hydrochloric acid Reaction: Fe two O three +6HCl=2FeCl three +3H two O Red rust gradually disappears, 6. Rust heel Dilute sulfuric acid reaction ：Fe two O three +3H two SO four =Fe two (SO four ) three +3H two O Solution turns yellow 7、 Cupric oxide React with dilute hydrochloric acid: CuO+2HCl=CuCl two +H two O Black copper oxide gradually disappears, 8、 Cupric oxide Follow Dilute sulfuric acid reaction ：CuO+H two SO four =CuSO four +H two O The solution turns blue. （2） Nature of alkali: (1) alkali solution can make Purple litmus test solution Turn blue, colorless Phenolphthalein test solution It turns red. (2) Alkali+majority Nonmetallic oxide =Salt+water (3) Alkali+acid=salt+water
(4) Alkali+some salts=another salt+another alkali
1、 sodium hydroxide Follow carbon dioxide Reaction: 2NaOH+CO two =Na two CO three +H two O 2. Sodium hydroxide and sulfur dioxide Reaction: 2NaOH+SO two =Na two SO three +H two O 3、 sodium hydroxide Follow Sulfur trioxide Reaction: 2NaOH+SO three =Na two SO four +H two O 4、 calcium hydroxide Reaction with carbon dioxide: Ca (OH) two +CO two =CaCO three ↓+H two O Clarify Limewater Turbid 5. Sodium hydroxide and Dilute sulfuric acid reaction ：2NaOH+H two SO four =Na two SO four +2H two O 6. Sodium hydroxide and Dilute hydrochloric acid Reaction: NaOH+HCl=NaCl+H two O 7、 quick lime React with water: CaO +H two O=Ca(OH) two （3） Properties of salt: (1) salt+some metals=another salt+another metal.
(2) Salt+some acids=another salt+another acid.
(3) Salt+some alkali=another salt+another alkali
(4) Salt+some salt=another salt+another salt
1、 Copper sulfate solution Reaction with iron: CuSO4+Fe=FeSO4+Cu iron surface is covered with red material, and the solution changes from blue to light green 2、 sodium carbonate Follow hydrochloric acid Reaction: Na2CO3+2HCl=2NaCl+H2O+CO2 ↑ Solid produced by bubbles decreases gradually 3、 sodium bicarbonate Reaction with hydrochloric acid: NaHCO3+HCl=NaCl+H2O+CO2 ↑ Solid produced by bubbles decreases gradually 4、 limestone Follow Dilute hydrochloric acid Reaction: CaCO3+2HCl= CaCl2 +H2O+CO2 ↑ Solid with bubbles decreases gradually 5、 silver nitrate React with dilute hydrochloric acid: AgNO3+HCl= AgCl ↓+ HNO3 There is white precipitation 6、 Barium chloride Follow Dilute sulfuric acid reaction ：BaCl2+H2SO4= BaSO4 ↓+2HCl has white precipitation 7、 calcium hydroxide root sodium carbonate Solution reaction: Ca (OH) 2+Na2CO3=2NaOH+CaCO3 ↓ white precipitate 8、 Silver nitrate solution Follow sodium hydroxide Solution reaction: AgNO3+NaCl=AgCl ↓+ NaNO3 There is white precipitation 9、 Barium chloride solution Follow sodium sulphate Solution reaction: BaCl2+Na2SO4=2NaCl+BaSO4 ↓ white precipitate Sequence table of metal activity
K Ca Na Mg Al Zn Fe Sn Pb (H) Cu Hg Ag Pt Au
(1) Most acids are soluble（ HCl 、 HNO3 、 H2CO3 yes volatility Concentrated H2SO4 Yes Water absorption 。） (2) Solubility of alkali: potassium, sodium, barium, ammonium, etc. are soluble, calcium, etc. are slightly soluble, and other alkalis are completely insoluble.
(3) Saliferous Solubility ： Potassium, sodium, ammonium, nitrate IV Salt solubilization 。 chloride except AgCl Except insoluble, the rest are completely soluble. sulfate except BaSO4 Insoluble, Ag2SO4 、 CaSO4 Except slightly soluble, the rest are completely soluble. carbonate Remove potassium, sodium ammonium salt Fully soluble MgCO3 Slightly outside, the rest are insoluble. 1、 Metathesis reaction Conditions for—— Product There is precipitation, or there is gas emission, or there is Weak electrolyte generate 2. Conditions for metal to react with acid——
(1) On Sequence table of metal activity Metal should be placed before hydrogen. （2） concentrated sulfuric acid 、 nitric acid Reacting with metal cannot generate hydrogen. (3) Iron replacement Reaction time , forming a compound of iron+2. 3. Conditions for reaction of metal with salt——
(1) On Sequence table of metal activity The simple metal is more active than the metal in salt. （2） reactant The salt in should be soluble. （3）K、 Ca 、Na、 Ba Other metals cannot react with salt to form another salt and another metal. 4. Conditions of salt reacting with salt—— reactant They should be soluble and the products should have precipitation. 5. Conditions for reaction of salt with alkali - reactants must be soluble, and products must have precipitation or gas.
Common name and chemical formula of common substances
Limestone, marble - CaCO3
Common salt - NaCl
Ice - H2O
Alcohol（ ethanol ）——C2H5OH Natural gas（ methane ）——CH4 Acetic acid（ acetic acid ）——CH3COOH Color of common substances
Red solid—— Cu 、Fe2O3、P（ phosphorus ） Black solid - C, CuO, Fe3O4 FeO 、 MnO2 White solid - KClO3 P2O5 、P（ White phosphorus ）CuSO4 (anhydrous copper sulphate ）KCl, NaCl kcn, etc Dark purple Solid—— KMnO4 Yellow solid - S Blue solid - CuSO4 · 5H2O blue flocculent precipitation - Cu (OH) 2
Reddish brown flocculent precipitation - common acid insoluble white precipitation of Fe (OH) 3—— BaSO4 、 AgCl It is dissolved in acid and emits white precipitate of gas that makes clarified lime water turbid—— BaCO3 、 CaCO3 Precipitation of isoinsoluble carbonate White precipitation soluble in acid but not producing gas -- precipitation of insoluble alkali such as Mg (OH) 2, Al (OH) 3
Blue solution - CuSO4, CuCl2, Cu (NO3) 2 and other solutions containing Cu2+
Light green solution - FeSO4, FeCl2 and other solutions containing Fe2+
Yellow solution—— FeCl3 , Fe2 (SO4) 3, Fe (NO3) 3 and other solutions containing Fe3+ Inspection and identification of substances
1. Inspection Dilute hydrochloric acid (or Cl -) - Take a small amount of the liquid to be tested and put it into a clean test tube, drop a few drops of AgNO3 solution and dilute HNO3, and white precipitate will be produced. 2. Inspection Dilute sulfuric acid (or SO42 -) - Take a small amount of the liquid to be tested and put it into a clean test tube, put a few drops of BaCl2 solution and dilute HNO3, and white precipitate will be produced. 3. Test CO32 -- Take a small amount of liquid to be tested into a clean test tube and drop a few drops of dilute HCl, which may produce gas that will make the clarified lime water turbid.
4. Inspection NH4+ ——Take a small amount of the substance to be tested in a clean test tube, and drop in an appropriate amount NaOH Solution and heating, wet Red litmus test paper Gas that turns blue is produced. 5. Identify dilute hydrochloric acid and dilute sulfuric acid - take a small amount of liquid to be tested in two clean test tubes, and drop several drops of BaCl2 solution into each tube. The original solution with white precipitate is Dilute sulfuric acid The original solution without phenomenon is Dilute hydrochloric acid 。 6. Identification of Ca (OH) 2 and NaOH solution - take a small amount of liquid to be tested in two clean test tubes, and inject CO2 gas (or several drops each Na2CO3 Solution), the original solution with white precipitation is Ca (OH) 2, and the original solution without phenomenon is NaOH 。 ◎ Supplement the following reaction equation:
1、 Copper hydroxide React with dilute hydrochloric acid: Cu(OH)2 +2HCl=CuCl2+2H2O blue precipitation disappears 2. Copper hydroxide heel Dilute sulfuric acid reaction : Cu (OH) 2+H2SO4=CuSO4+2H2O turns into blue solution 3. Sodium hydroxide and Copper sulfate solution Reaction: 2NaOH+CuSO4=Na2SO4+Cu (OH) 2 ↓ Blue precipitate is produced 4. Sodium hydroxide and Ferric chloride Solution reaction: 3NaOH+FeCl3= Fe(OH)3 ↓+3NaCl has reddish brown precipitation ◎ Judge the solution Acid-base property ——Use indicator , solution PH ——It is expressed in pH. 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
neutral
← Acidity enhanced alkalinity enhanced →
PH<7 indicates acid, red, colorless
PH=7, neutral, purple, red
PH ＞ 7 indicates alkaline, blue or red
◎ desiccant Selection of: 1、 concentrated sulfuric acid Driable: Acid gas (e.g. CO2, SO2, SO3 NO2 、HCl、） Neutral gas (e.g. H2 O2 、 N2 、 CO ） ※ Do not dry Alkaline gas (e.g.: NH3 ） 2. Sodium hydroxide solid quick lime 、 Alkali lime Driable: Alkaline gas (e.g. NH3) Neutral gas (such as H2, O2, N2, CO)
※ Acid gas cannot be dried because it will react with it (such as CO2 SO2、SO3、NO2、HCl。）
3. The anhydrous copper sulfate solid changes from white to blue when encountering water, which can detect the existence of water and absorb steam 。 
