Reaction of chlorine gas with sodium hydroxide* (reaction phenomenon of chlorine gas with sodium hydroxide)

Posted on December 10, 2022

Reaction of Chlorine and Sodium Hydroxide*

Summary of Key Points

Original 2020-11-12 15:00 Centennial Spirit

1. Properties of sodium and its compounds

1. Reaction of sodium with air

①Sodium is slow in air Oxidation: 4Na+O2==2Na2O ②Sodium burns in air: 2Na+O2△(====)Na2O 2.

One mole of sodium metal reacts fully with oxygen, and one mole of electrons is transferred.

2. Sodium reacts with water

Na+2H2O = 2NaOH+H2 ↑(The reactant coefficient is 2)

Phenomenon: ①Sodium floats on the water surface ; (2) Melted into silvery white particles; ③Swimming up and down the water surface; (4) Accompanied by whistling sound; (Floating Fragrance Red)

The reaction between sodium and acid: first acid and then water.

Reaction with sodium: with water

Reaction between sodium and salt: first water and then salt.

Any solution has gas, saturated or insoluble has precipitation.

Sodium peroxide Na2O2

Oxide

Na2O

Na2O2

Oxygen valence

――2

――1

Building Conditions

Normal Temperature

Hot

Color, State

White solid

Light yellow powder

Reaction to H2O

Na2O+H2O=2NaOH

2Na2O2+ 2H2O=4NaOH+O2↑

Reaction with CO2

Na2O+CO2= Na2CO3

2na 2 o 2+2co 2 = 2na 2 co 3+O2 ↓

Reaction with acid

Na2O+2HCl=2NaCl+ H2O

2Na2O2+4HCl=4NaCl+2H2O+O2↑

Heat Stability

Unstable and easily oxidized to Na2O2.

Relatively stable

Bleaching

No

Yes

1. Sodium peroxide reacts with water: 2Na2O2+2H2O=4NaOH+O2↑ (the reactant coefficient is 2)

2. The reaction of sodium peroxide and carbon dioxide: 2Na2O2+2CO2=2Na2CO3+O2 (the reactant coefficient is 2)

Xg hydrogen gas mixed with carbon monoxide gas,After complete combustion, add sodium peroxide to increase Xg weight.

Sodium carbonate and sodium bicarbonate NaHCO3 and Na2CO3

Comparison of sodium carbonate and sodium bicarbonate

Soda

Sodium bicarbonate

Popular names

Or soda ash.

Sodium Bicarbonate

Color State

White Crystals

Fine White Crystals

Water Soluble

Soluble in water, alkaline solution makes phenolphthalein red.

Soluble in water (but not as soluble as Na2CO3), the solution is alkaline (phenolphthalein turns light red).

Thermal stability

Stable, not easy to decompose when heated.

Easily decomposed by heat

2NaHCO3 == Na2CO3+CO2↑+H2O

Reaction with acid

CO32- + H+= HCO3-

HCO3-+ H+ = CO2↑+H2O

Under the same conditions, the CO2 release rate of sodium bicarbonate is faster than that of sodium carbonate.

Reaction with base

na2co 3+Ca(OH)2 = CaCO3+2 NaOH Co32-Metathesis reaction with metal cation

Sodium bicarbonate + hydrogen Sodium Oxide = Sodium Carbonate + H2O

HCO3- +OH-= H2O+CO32-

With H2O and Carbon Dioxide

Sodium Carbonate + Carbon Dioxide + H2O = Carbonic Acid Sodium hydrogen

CO32-+H2O+CO2 =H CO3-

No reaction

1. Add dilute hydrochloric acid: na2co 3 +HCl = NaCl+nah co 3+HCl = NaCl+H2O+CO2 ↑ (bubbles will appear later)

Add dilute hydrochloric acid to sodium bicarbonate: NaHCO3+ HCl = NaCl+H2O+CO2↑ (will A large amount of gas will be generated quickly)

Add sodium carbonate solution to hydrochloric acid: Na2CO3+ 2HCl = 2NaCl+H2O+CO2↑ (slowly generate a large amount of gas)

2. Add sodium carbonate solution Carbon dioxide is introduced into the medium: Na2CO3+CO2+H2O=2NaHCO3

3. Sodium bicarbonate is thermally decomposed: 2nachco3△ (= = = =) Na2CO3+H2O+CO2 ↑.

4. The reaction of sodium hydroxide and sodium bicarbonate: NaOH+NaHCO3=Na2CO3+H2O

The substance that distinguishes sodium carbonate and sodium bicarbonate can be acid or salt, but not It is alkali.

Two. Properties of Chlorine and Its Compounds

1. Comparison of liquid chlorine, fresh chlorine water and long-term chlorine water (Illumination) 2HCl+O Youyou Resource Network 2 ↑Among them, HCLO hypochlorous acid has strong oxidizing and drifting properties, and plays the role of disinfection and bleaching. Hypochlorous acid is weakly acidic, unstable, decomposes when exposed to light or heat, and will become invalid if left for a long time.

(2) Prepare bleaching powder liquid, bleaching powder and bleaching powder concentrate

Bleaching solution: Cl2+2NaOH = NaCl+NaClO+H2O. Its active ingredient NaClO is much more stable than HClO and can be stored for a long time.

*** Bleach powder (available chlorine 35%) and bleach powder concentrate (fully reacted available chlorine 70%): 2cl 2+2ca(oh)2 = CaCl 2+ca(clo)2+2h2o

3, the nature of chlorine

Na+Cl2 ignition (= = = = =) 2Na+Cl2 (white smoke) H2+Cl2 ignition (== ===) 2HCl (white mist) phosphorus burns in chlorine (white smoke)

4. Reaction of chlorine and sodium hydroxide Cl2+2NaOH=NaCl+NaClO+H2O (chlorine tail gas treatment)

5. Bleaching powder (chlorine can be introduced into lime slurry) 2cl 2+2ca(OH)2=CaCl 2+Ca(ClO)2+2H2O CaCl 2 and Ca(ClO)2 are called bleaching powder.

Bleaching powder deteriorates in air: Ca(ClO)2+CO2+H2O=CaCO3↓+2HClO

Third, the amount of substance is The physical quantity relationship of the center

1. Physical quantity-the unit of substance-mole (mol)

①n= N/NA N represents the number of particles NA Gadereau constant NA≈6.021023 mol-1

2. The molar mass of the substance m

②n= m/M

m represents the mass of the substance. m is the molar mass, which is numerically equal to the relative atomic mass or molecular mass of the substance. The unit is GMOL One.

3. The molar volume of the gas Vm

③n=V/Vm V is the volume of the gas in liters (L) Vm is the molar volume of the gas. Under standard conditions, 1 mole of gas is 22.4 liters.

When the temperature and pressure are constant, Vm is a constant value, and the unit of Vm is L mol-1. Avogadro’s Law: At the same temperature and pressure, any gas of the same volume contains the same number of molecules. Therefore, it is also called the law of four sameness, also called the law of five sameness (five sameness refers to the same temperature, same pressure, same volume,same number of molecules, same number of substances).

Corollary: Law

(1) At the same temperature and pressure, V1/V2=n1/n2

(2) At the same temperature and pressure Under the volume, p1/p2=n1/n2=N1/N2

(3) When the mass is equal to the same temperature and pressure, V1/V2=M2/M1

4. The number concentration of the solute in the solution C

④n=cV C is the concentration of the solute in the solution, the unit is mol·L-1v, the volume of the solution, the unit is L (L)

5. Preparation and error analysis of a concentrated solution of a certain substance

(1) The volumetric flask is used to prepare a concentrated solution of a certain amount of substance.