Nitric acid and its salts

Prepared by the teacher of chemistry of KOU VO "CLPDO" Savrasova M.I.


Remember!

  • What are the oxidation states of nitrogen in its oxides?
  • What oxides of nitrogen do you know?
  • Tell us about N2O, NO, NO2?
  • Which of these nitrogen compounds is the most important in terms of economic production value?


  • The study of the properties of nitric acid,
  • Its significance in human economic activity.

The structure of the molecule

HNO3- molecular formula


Physical properties of nitric acid

  • Review the samples of nitric acid given to you.
  • Check color, transparency, water solubility. Record your observations in your notebook.

Chemical properties of nitric acid

  • Very strong acid
  • Dissociates in aqueous solution:
  • H NO3 ↔NO3 + H
  • Interacts:
  • with metals
  • Cu +4HNO3 = Cu(NO3)2 +2NO2 +2H2O
  • With metal oxides:
  • CuO + 2HNO3= Cu(NO3)2 + H2O
  • With metal hydroxides
  • Cu(OH)2 + 2HNO3 = Cu(NO3)2 + 2H2O

Special properties

  • Cu +4HNO3 = Cu(NO3)2 +2NO2 +2H2O
  • When heated, a brown gas is released, it is toxic to humans.

Qualitative reaction to nitrate ions


Nitric acid production

  • Air nitrogen oxidation.
  • Additional oxidation of nitric oxide +2 to nitric oxide +4
  • Obtaining nitric acid.

Write equations for the corresponding reactions.


The use of nitric acid

Explosives

Medications

Nitric acid

artificial fibers

Dyes

fertilizers


Nitrates

  • NaNO3
  • NH4NO3
  • Ca(NO3)2
  • Salts of nitric acid are also called saltpeters. They are used in the production of matches, gunpowder, fertilizers.

Anchoring

  • 2KNO3 →2KNO2 +O2
  • Qualitative reaction to nitrates.
  • Decide whether the following statement is correct or incorrect:
  • 1. Nitric acid is a heavy, poorly soluble liquid in water.
  • 2. Nitric acid is a yellowish liquid, highly soluble in water.

Anchoring

  • 3. Nitric acid forms salts - nitrites.
  • 4. Nitric acid forms salt-nitrates.
  • 5. In nitric acid, nitrogen is +5.
  • 6. In nitric acid, nitrogen is +4.
  • 7.Nitric acid does not react with metals after hydrogen.

Anchoring

8. Nitric acid does not react with any metals.

9. Nitric acid reacts with metal oxides.

10. Nitric acid reacts with bases.

11. Nitric acid reacts with salts.

12. Nitric acid can be detected by its reaction with copper.

13. Nitric acid can be recognized by its interaction with coal.


Test your knowledge:

  • Right answers:
  • 1,4,5, 9,10,11,12.

Homework

§29 exercises 1-4

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Slides captions:

This substance was described by the Arab chemist in the 8th century Jabir ibn Hayyan (Geber) in his work “The Coachman of Wisdom”, and since the 15th century this substance has been mined for industrial purposes. - Thanks to this substance, the Russian scientist V.F. Petrushevsky in 1866 for the first time received dynamite. - This substance is the progenitor of most explosives (for example, TNT, or Tol). - This substance is a component of rocket fuel, it was used for the engine of the world's first Soviet jet aircraft BI - 1. - This substance, mixed with hydrochloric acid, dissolves platinum and gold, recognized as the "king" of metals. The mixture itself, consisting of 1 volume of this substance and 3 volumes of hydrochloric acid, is called "royal vodka".

A LITTLE HISTORY Monk-alchemist Bonaventure in 1270, in search of a universal solvent "alkahest", decided to heat a mixture of iron sulphate with saltpeter. The vessel containing the mixture soon filled with a red-brown "smoke". The monk froze in amazement, then turned off the fire and saw a yellowish liquid begin to drip into the receiver flask. It worked on all metals, even on silver and mercury. Alchemists thought that the red smoke sitting in the liquid is a demon that controls one of the elements of nature - water. Therefore, the yellowish liquid was called "strong water" or "strong vodka". This name survived until the time of M.V. Lomonosov. What is this substance now called?

2 FeSO 4 7H 2 O + 4 KNO 3 \u003d Fe 2 O 3 + 2 K 2 SO 4 + 2HNO 3 + 13H 2 O + 2NO 2

NITRIC ACID

HNO 3 - nitric acid Physical properties 1. Molar mass 63.016 g / mol 2. Colorless liquid with a pungent odor, "smokes" in air, T bp. \u003d 86 3. Highly soluble in water (strong monobasic acid) 4. The molecule has a flat structure 5. Valence (N) \u003d IV 6. Oxidation state (N) \u003d + 5

Chemical properties Common with other acids Specific

1) Changes the color of indicators (dissociation) HNO 3  2) Interaction with basic and amphoteric oxides CuO + 2HNO 3  3) Interaction with bases and ammonia KOH + HNO 3  NH 3 +HNO 3  4) Interaction with salts Na 2 CO 3 +2HNO 3  Common with other acids

Specific properties - interaction with metals REMEMBER! In the interaction of nitric acid of any concentration with metals, hydrogen is never released. The products depend on the metal and acid concentration.

Diluted

concentrated

Interaction with non-metals When interacting with non-metals, an acid is formed, in which the non-metal has the highest oxidation state, and the product according to the scheme: NO not Me + HNO 3 NO 2 P + 5HNO 3 (c.)  H 3 PO 4 + 5NO 2 + H 2 O 3P + 5HNO 3 (p) + 2H 2 O  3H 3 PO 4 + 5NO

Action on organic substances When interacting with concentric nitric acid, proteins are destroyed and acquire a yellow color. Under the action of nitric acid, paper, oil, wood, coal ignite.

A mixture of concentrated nitric and hydrochloric acids (ratio by volume 1:3) is called aqua regia; it dissolves even noble metals. A mixture of HNO 3 concentrations of 100% and H 2 SO 4 concentrations of 96% at a ratio by volume of 9:1 is called melange.

Use Production: NH 4 NO 3 mineral fertilizers Na, K, Ca nitrates, etc. in hydrometallurgy obtaining explosives, H 2 SO 4 , H 3 PO 4 , aromatic nitro compounds, dyes, rocket fuel. etching of metals, obtaining semiconductors


Nitric acid.

Completed by: teacher of chemistry and biology

Muravieva Nina Ivanovna


  • nitrogen oxides
  • The structure of the nitric acid molecule.
  • Obtaining nitric acid
  • physical properties.
  • properties of nitrates.
  • Laboratory experiment
  • The use of nitric acid and nitrates

nitrogen oxides

Table

Comparison of nitrogen oxides, acids and salts

Remember and write the formulas of nitrogen oxides. Which oxides are called salt-forming, which are non-salt-forming? Why?


The structure of the nitric acid molecule.

Structural formula of nitric acid


Obtaining nitric acid

In the laboratory NaNO 3 (TV.) + H 2 SO 4 (CONC) → NaHSO 4 + HNO 3

In industry

4NH 3 + 5O 2 → 4NO + 6H 2 O + Q

2NO + O 2 → 2NO 2 (on cooling)

4NO 2 + O 2 + 2H 2 O ↔ 4HNO 3 + Q


Obtaining nitric acid by oxidation of ammonia with atmospheric oxygen.

Ammonia-air mixture


Scheme for the production of nitric acid in industry

2NO2+O2 →2NO2

3NO2+H2O →2HNO 3 +NO

catalyst

contact device

Oxidation tower

absorption tower


contact device

Ammonia-air

Catalyst

nitrous gases


Physical properties

Pure nitric acid is a colorless fuming liquid with a pungent, irritating odor. Concentrated nitric acid is usually colored yellow. This color gives it nitric oxide (IV), which is formed due to the partial decomposition of nitric acid and dissolves in it.


  • Nitric acid is a strong oxidizing agent, concentrated nitric acid oxidizes sulfur to sulfuric acid, and phosphorus to phosphoric acid, some organic compounds (for example, amines and hydrazines, turpentine) spontaneously ignite upon contact with concentrated nitric acid.



Properties of nitrates

Me is to the left of Mg

MeNO 2 + O 2 ↓

Me is between Mg and Cu

MeO + NO 2 + O 2

Me are to the right of Cu

Me + NO 2 + O 2


  • Carefully add a few thin pieces of copper wire to a test tube with concentrated nitric acid. The reaction proceeds without heating, students observe a change in the color of the solution and the evolution of red-brown NO2 gas

check yourself

Cu + HNO 3 (END) = Сu(NO 3 ) 2 + NO 2 + H 2 O


  • Carefully add a few thin pieces of copper wire to the test tube with dilute nitric acid. The reaction proceeds when heated. Observe the color change of the solution and the evolution of colorless NO gas
  • Write an equation for the reaction taking place

Test yourself

Cu + HNO3(razb.) = Cu(NO3)2 + NO + H2O

Cu 0 – 2e = Cu +1 3 the reducing agent is oxidized

N +5 + 3e = N +2 2 oxidizer is reduced

3Cu + 8HNO3 = 3Cu(NO3)2 + 2NO + 4H2O


The use of nitric acid and nitrates

MEDICINES

DYES

COLLODION

EXPLOSIVES

FILM

AQUA REGIA

MINERAL FERTILIZERS


  • Why is the oxidation state of nitrogen in nitric acid +5, and the valence is four?
  • What metals does nitric acid not react with?
  • You need to recognize hydrochloric and nitric acids, there are three metals on the table - copper, aluminum and iron. How will you do it and why?

"Salt of nitric acid" - What happens when sodium nitrate decomposes? Physical properties of nitrates. Specify the oxidizing agent, reducing agent. Chemical properties of nitrates. Know and be able. A solution of nitric acid reacts with each of the substances. What conclusions did the young chemist come to? All nitrates are thermally unstable. An entertaining story.

"Theories of acids and bases" - For example, which acid is stronger acetic (CH3COOH or chloroacetic ClCH2COOH? 2. Addition reactions. The strength of the base R3N in water can be estimated by considering the equilibrium: Gilbert Newton Lewis. The measure of acidity is the equilibrium constant, called the acidity constant (Ka) Svante-August Arrhenius.

"Acetic acid" - What are acids? Not all fruits and vegetables contain acids. Acids. Formic acid was first obtained in its pure form in 1749. Andreas Sigismund Marggraf. Journey into the world of acids. How to detect acids? Formic acid solution. The history of the discovery of acids. Acids have a similar composition. What substances are acids?

"Acid rain" - New ozone holes are expected to appear in the Baltic region. Aluminum can cause disease. It can be assumed that what happens to wild species of animals when forests die. We, and almost all living things, need fresh water. Along with the death of lakes, the degradation of forests also becomes apparent.

"Carboxylic acids" - Repeat the definition of carboxylic acids. Obtaining carboxylic acids. The structure of the carboxyl group. carboxylic acids. What are called carboxylic acids? Esters nomenclature. All carboxylic acids have a functional group. Molecules of carboxylic acids form dimers. Chemical properties of carboxylic acids.

"Nucleic acids" - 1892. - chemist Lilienfeld isolated thymonucleic acid from the goiter gland in 1953. nitrogenous base. Laboratory practice. The structure of nucleotides (differences). 1868 - German chemist F. Miescher discovered nucleic acids. The biological role of nucleic acids. Comparative characteristics. Length of DNA molecules (American biologist G.Taylor).