Iron(II) compounds

Iron compounds with the oxidation state of iron +2 are unstable and are easily oxidized to iron (III) derivatives.

Fe 2 O 3 + CO = 2FeO + CO 2.

Iron (II) hydroxide Fe(OH) 2 when freshly precipitated, it has a grayish-green color, does not dissolve in water, decomposes at temperatures above 150 ° C, and quickly darkens due to oxidation:

4Fe(OH) 2 + O 2 + 2H 2 O = 4Fe(OH) 3.

It exhibits mild amphoteric properties with a predominance of basic ones, and easily reacts with non-oxidizing acids:

Fe(OH) 2 + 2HCl = FeCl 2 + 2H 2 O.

Interacts with concentrated solutions alkalis when heated to form tetrahydroxoferrate (II):

Fe(OH) 2 + 2NaOH = Na 2.

Shows restorative properties, upon interaction with nitric or concentrated sulfuric acid, iron (III) salts are formed:

2Fe(OH) 2 + 4H 2 SO 4 = Fe 2 (SO 4) 3 + SO 2 + 6H 2 O.

It is obtained by reacting iron (II) salts with an alkali solution in the absence of atmospheric oxygen:

FeSO 4 + 2NaOH = Fe(OH) 2 + Na 2 SO 4.

Iron (II) salts. Iron (II) forms salts with almost all anions. Typically, salts crystallize in the form of green crystalline hydrates: Fe(NO 3) 2 6H 2 O, FeSO 4 7H 2 O, FeBr 2 6H 2 O, (NH 4) 2 Fe(SO 4) 2 6H 2 O (salt Mora), etc. Salt solutions have a pale green color and, due to hydrolysis, an acidic environment:

Fe 2+ + H 2 O = FeOH + + H +.

They exhibit all the properties of salts.

When standing in air, they are slowly oxidized by dissolved oxygen to iron (III) salts:

4FeCl 2 + O 2 + 2H 2 O = 4FeOHCl 2.

Qualitative reaction for the Fe 2+ cation - interaction with potassium hexacyanoferrate (III) (red blood salt):

FeSO 4 + K 3 = KFe↓ + K 2 SO 4

Fe 2+ + K + + 3- = KFe↓

As a result of the reaction, a precipitate is formed blue- iron (III) hexacyanoferrate (II) - potassium.

The oxidation state +3 is characteristic of iron.

Iron (III) oxide Fe 2 O 3 - The substance is brown in color and exists in three polymorphic modifications.

Shows mild amphoteric properties with a predominance of basic ones. Reacts easily with acids:

Fe 2 O 3 + 6HCl = 2FeCl 3 + 3H 2 O.

It does not react with alkali solutions, but upon fusion it forms ferrites:

Fe 2 O 3 + 2NaOH = 2NaFeO 2 + H 2 O.

Shows oxidizing and reducing properties. When heated, it is reduced by hydrogen or carbon monoxide (II), exhibiting oxidizing properties:

Fe 2 O 3 + H 2 = 2FeO + H 2 O,

Fe 2 O 3 + CO = 2FeO + CO 2.

In the presence of strong oxidizing agents alkaline environment exhibits reducing properties and is oxidized to iron (VI) derivatives:

Fe 2 O 3 + 3KNO 3 + 4KOH = 2K 2 FeO 4 + 3KNO 2 + 2H 2 O.

At temperatures above 1400°C it decomposes:

6Fe 2 O 3 = 4Fe 3 O 4 + O 2.

Obtained by thermal decomposition of iron (III) hydroxide:

2Fe(OH) 3 = Fe 2 O 3 + 3H 2 O

or pyrite oxidation:

4FeS 2 + 11O 2 = 2Fe 2 O 3 + 8SO 2.

FeCl 3 + 3KCNS = Fe(CNS) 3 + 3KCl,

• Designation - Fe (Iron);
• Period - IV;
• Group - 8 (VIII);
• Atomic mass - 55.845;
• Atomic number - 26;
• Atomic radius = 126 pm;
• Covalent radius = 117 pm;
• Electron distribution - 1s 2 2s 2 2p 6 3s 2 3p 6 3d 6 4s 2 ;
• melting temperature = 1535°C;
• boiling point = 2750°C;
• Electronegativity (according to Pauling/according to Alpred and Rochow) = 1.83/1.64;
• Oxidation state: +8, +6, +4, +3, +2, +1, 0;
• Density (no.) = 7.874 g/cm3;
• Molar volume = 7.1 cm 3 /mol.

Iron compounds:

Iron is the most common metal in earth's crust(5.1% by weight) after aluminum.

On Earth, free iron is found in small quantities in the form of nuggets, as well as in fallen meteorites.

Industrially, iron is mined from iron ore deposits from iron-containing minerals: magnetic, red, brown iron ore.

It should be said that iron is part of many natural minerals, causing their natural color. The color of minerals depends on the concentration and ratio of iron ions Fe 2+ /Fe 3+, as well as on the atoms surrounding these ions. For example, the presence of impurities of iron ions affects the color of many precious and semi-precious stones: topazes (from pale yellow to red), sapphires (from blue to dark blue), aquamarines (from light blue to greenish blue), etc.

Iron is found in the tissues of animals and plants; for example, about 5 g of iron is present in the body of an adult. Iron is a vital element; it is part of the hemoglobin protein, participating in the transport of oxygen from the lungs to tissues and cells. With a lack of iron in the human body, anemia (iron deficiency anemia) develops.

Rice. Structure of the iron atom.

The electronic configuration of the iron atom is 1s 2 2s 2 2p 6 3s 2 3p 6 3d 6 4s 2 (see Electronic structure of atoms). In education chemical bonds with other elements, 2 electrons located on the outer 4s level + 6 electrons of the 3d sublevel (8 electrons in total) can participate, so in compounds iron can take oxidation states +8, +6, +4, +3, +2, + 1, (the most common are +3, +2). Iron has average chemical activity.

Rice. Iron oxidation states: +2, +3.

Physical properties of iron:

• silver-white metal;
• in its pure form it is quite soft and plastic;
• has good thermal and electrical conductivity.

Iron exists in the form of four modifications (differing in structure crystal lattice): α-iron; β-iron; γ-iron; δ-iron.

Chemical properties of iron

• reacts with oxygen, depending on the temperature and oxygen concentration, various products or a mixture of iron oxidation products (FeO, Fe 2 O 3, Fe 3 O 4) can be formed:
  3Fe + 2O 2 = Fe 3 O 4;
• iron oxidation low temperatures:
  4Fe + 3O 2 = 2Fe 2 O 3;
• reacts with water vapor:
  3Fe + 4H 2 O = Fe 3 O 4 + 4H 2;
• finely crushed iron reacts when heated with sulfur and chlorine (iron sulfide and chloride):
  Fe + S = FeS; 2Fe + 3Cl 2 = 2FeCl 3;
• at high temperatures ah reacts with silicon, carbon, phosphorus:
  3Fe + C = Fe 3 C;
• Iron can form alloys with other metals and non-metals;
• iron displaces less active metals from their salts:
  Fe + CuCl 2 = FeCl 2 + Cu;
• With dilute acids, iron acts as a reducing agent, forming salts:
  Fe + 2HCl = FeCl 2 + H 2;
• with dilute nitric acid, iron forms various acid reduction products, depending on its concentration (N 2, N 2 O, NO 2).

Obtaining and using iron

Industrial iron is obtained smelting cast iron and steel.

Cast iron is an alloy of iron with impurities of silicon, manganese, sulfur, phosphorus, and carbon. The carbon content in cast iron exceeds 2% (in steel less than 2%).

Pure iron is obtained:

• in oxygen converters made of cast iron;
• reduction of iron oxides with hydrogen and divalent carbon monoxide;
• electrolysis of the corresponding salts.

Cast iron is obtained from iron ores by reduction of iron oxides. Iron smelting is carried out in blast furnaces. Coke is used as a heat source in a blast furnace.

A blast furnace is a very complex technical structure several tens of meters high. It is lined with refractory bricks and protected by an outer steel casing. As of 2013, the largest blast furnace was built in South Korea by the steel company POSCO at the Gwangyang Metallurgical Plant (the furnace volume after modernization was 6,000 cubic meters with an annual capacity of 5,700,000 tons).

Rice. Blast furnace.

The process of smelting cast iron in a blast furnace continues continuously for several decades until the furnace reaches its end.

Rice. The process of smelting iron in a blast furnace.

• enriched ores (magnetic, red, brown iron ore) and coke are poured through the top of the blast furnace;
• processes of reduction of iron from ore under the influence of carbon monoxide (II) occur in the middle part of the blast furnace (mine) at a temperature of 450-1100°C (iron oxides are reduced to metal):
  • 450-500°C - 3Fe 2 O 3 + CO = 2Fe 3 O 4 + CO 2 ;
  • 600°C - Fe 3 O 4 + CO = 3FeO + CO 2 ;
  • 800°C - FeO + CO = Fe + CO 2 ;
  • part of the divalent iron oxide is reduced by coke: FeO + C = Fe + CO.
• In parallel, the process of reduction of silicon and manganese oxides (included in iron ore in the form of impurities) occurs; silicon and manganese are part of the melting iron:
  • SiO 2 + 2C = Si + 2CO;
  • Mn 2 O 3 + 3C = 2Mn + 3CO.
• During the thermal decomposition of limestone (introduced into a blast furnace), calcium oxide is formed, which reacts with silicon and aluminum oxides contained in the ore:
  • CaCO 3 = CaO + CO 2;
  • CaO + SiO 2 = CaSiO 3;
  • CaO + Al 2 O 3 = Ca(AlO 2) 2.
• at 1100°C the process of iron reduction stops;
• below the shaft there is steam, the widest part of the blast furnace, below which there is a shoulder, in which coke burns out and liquid smelting products are formed - cast iron and slag, accumulating at the very bottom of the furnace - the forge;
• In the upper part of the hearth at a temperature of 1500°C, intensive combustion of coke occurs in a stream of blown air: C + O 2 = CO 2 ;
• passing through hot coke, carbon monoxide (IV) is converted into carbon monoxide (II), which is a reducing agent for iron (see above): CO 2 + C = 2CO;
• slags formed by silicates and calcium aluminosilicates are located above the cast iron, protecting it from the action of oxygen;
• through special holes located at different levels of the hearth, cast iron and slag are discharged out;
• Most of the cast iron is used for further processing - steel smelting.

Steel is smelted from cast iron and scrap metal using the converter method (the open-hearth method is already outdated, although it is still used) or by electric smelting (in electric furnaces, induction furnaces). The essence of the process (cast iron processing) is to reduce the concentration of carbon and other impurities through oxidation with oxygen.

As mentioned above, the carbon concentration in steel does not exceed 2%. Thanks to this, steel, unlike cast iron, can be forged and rolled quite easily, which makes it possible to make a variety of products from it that have high hardness and strength.

The hardness of steel depends on the carbon content (the more carbon, the harder the steel) in a particular grade of steel and heat treatment conditions. During tempering (slow cooling), the steel becomes soft; When quenched (rapid cooling), the steel becomes very hard.

To give steel the required specific properties, alloying additives are added to it: chromium, nickel, silicon, molybdenum, vanadium, manganese, etc.

Cast iron and steel are the most important structural materials in the vast majority of sectors of the national economy.

Biological role of iron:

• the adult human body contains about 5 g of iron;
• iron plays an important role in the functioning of hematopoietic organs;
• iron is part of many complex protein complexes (hemoglobin, myoglobin, various enzymes).

Iron(II) sulfate, iron(III) sulfate.

Chemical properties

Ferrous sulfate – inorganic compound, salt formed sulfuric acid and iron. The substance is odorless and non-volatile. The anhydrous form has the form of colorless, opaque, small hygroscopic crystals. Crystal hydrates have a characteristic greenish-blue color, tetrahydrates are green. Chemical formula of Iron Sulfate 2: FeSO4, racemic: O4SFe. The taste of the compound is astringent, with a metallic taste. The product dissolves well in water. Molecular weight = 151.9 grams per mole.

The substance is released from iron sulfate . Solution Fe(2) sulfate under the influence of oxygen it is oxidized and becomes Iron Sulfate 3. It decomposes at temperatures above 480 degrees Celsius into oxides.

Iron sulfate 2 can be obtained by exposure to diluted sulfuric acid for iron scraps; as a by-product of the etching reaction of iron sheets, when removing scale, during oxidative roasting of pyrite.

Hydrolysis of Iron Sulfate 2 proceeds through the cation in acidic environment. First stage of hydrolysis: Fe2+ + SO42- + HOH ↔ FeOH+ + SO42- + H+; theoretically, the second stage of hydrolysis can also occur: FeOH+ + SO42- + HOH ↔ Fe(OH)2↓ + SO42- + H+.

The substance is used:

• for painting products and wool fabric in black color, in the production of ink, in wood preservation;
• in chemical dosimetry, for the treatment of garden trees in agriculture;
• in medicine during treatment iron deficiency anemia .

Iron sulfate 3 or iron tetrasulfide 6 3 - These are light yellow paramagnetic small crystals. The substance dissolves well in water, slowly in ethyl alcohol. Chemical formula of Ferrous Sulfate 3: Fe2(SO4)3, racemic: Fe2O12S3. The substance has the ability to crystallize in the form of crystalline hydrates Fe2(SO4)3nH2O. Highest value has iron(III) sulfate nonahydrate . Aqueous solutions acquire a red-brown color due to the hydrolysis reaction occurring on the cation. The compound decomposes when exposed to hot water and high temperatures. At 98 degrees nonahydrate turns into tetrahydrate , at temperatures above 125 degrees - in monohydrate and above 175 – anhydrous Fe sulfate , which at temperatures above 600 degrees decomposes into oxides of sulfur and iron.

The substance is used:

• when processing copper ore, for cleaning waste water, industrial and municipal wastewater;
• when dyeing fabrics and tanning in leather production;
• as a flotation regulator, as a catalyst for certain reactions or as an oxidizing agent;
• in medicine as a hemostatic agent.

Pharmacological action

Antianemic, eliminating iron deficiency. Hemostatic (Ferric Sulfate 3).

Pharmacodynamics and pharmacokinetics

Iron is the main microelement found in, myoglobin and other blood components. The substance takes part in redox reactions, binds and transports oxygen molecules throughout the body, stimulates hematopoiesis And erythropoiesis . Ferrous sulfate ensures the synthesis of all iron-containing metabolites. After admission Fe with food, it is absorbed in the duodenum and transferred to tissue depots with the help of enzymes transfertins .

After taking the medicine orally, its active components are completely absorbed by the body. The maximum concentration in the blood is observed after 2-4 hours.

Indications for use

The product is used:

• for treatment and prevention iron deficiency anemia in children and adults;
• in case of impaired absorption of iron from the digestive tract;
• in patients with an increased need for iron, during breastfeeding, during intensive growth, with an unbalanced diet;
• in chronic cases, accompanied by secretory insufficiency;
• at some stages of treatment B12 deficiency anemia ;
• during exacerbation;
• during rehabilitation after gastric resection ;
• for the treatment of premature babies;
• for stimulation during infectious diseases and during;
• when treating patients with achlorhydria , chronic , Crohn's disease , syndrome malabsorption .

Contraindications

Iron sulfate 2 is contraindicated for use:

• when on the means;
• in patients with metabolic disorders in the body, with hemosiderosis , hemochromatosis ;
• patients with gastrointestinal dysfunction that interferes with iron absorption;
• with aplastic and hemolytic anemia ;
• patients with thalassemia .

Side effects

Adverse reactions during treatment with Ferrous Sulfate do not occur frequently.

May appear:

• , headache , general weakness and irritability, epileptic syndrome And ;
• feeling of pressure in the chest, or nausea;
• toothache, pain in the epigastric region;
• skin rashes, itching, sore throat;
• very rarely - anaphylactic reactions .

Instructions for use (Method and dosage)

The medicine is prescribed orally. The minimum effective dosage in terms of elemental iron is 100 mg. Maximum quantity medications that can be taken – up to 400 mg.

For preventive purposes, 30 to 60 mg of elemental iron per day is prescribed.

Overdose

In case of overdose, adverse reactions from taking the medicine intensify. There are: diarrhea , nausea, abdominal pain, vomiting, and increased heart rate, increased capillary permeability, possible cardiovascular collapse . As a therapy, the stomach is washed, administered deferoxamine for binding iron ions.

Interaction

When combined with, the absorption of iron preparations improves.

Combined intake of sulfate and antacids with magnesium, aluminum, calcium, penicillamine And cholestyramine slows down iron absorption.

When a drug is combined with GCS, it mutually enhances erythropoiesis .

Storage conditions

The drugs are stored in a dry, dark, cool place in the original packaging. Do not use the medicine after the expiration date.

Special instructions

During treatment with Ferrous Sulfate II, black stool and darkening of tooth enamel may occur.

With kidney and liver diseases, iron can accumulate in the body.

Particular care is taken when treating patients with peptic ulcer of the stomach and duodenum , at ulcerative colitis And enteritis .

Abstract on the topic:

Iron(III) sulfate

Plan:

Introduction

• 1 Physical properties
• 2 Being in nature
  • 2.1 Mars
• 3 Receipt
• 4 Chemical properties
• 5 Use
Notes

Introduction

Iron(III) sulfate(lat. Ferrum sulfuricum oxydatum, German Eisensulfate (oxyd) Ferrisulfate ) - inorganic chemical compound, salt, chemical formula - .

1. Physical properties

Anhydrous iron(III) sulfate - light yellow, paramagnetic, very hygroscopic crystals of monoclinic system, space group P2 1 /m, unit cell parameters a= 0.8296 nm, b= 0.8515 nm, c= 1.160 nm, β = 90.5°, Z = 4. There is evidence that anhydrous iron sulfate forms orthorhombic and hexagonal modifications. Soluble in water and acetone, insoluble in ethanol.

Crystallizes from water in the form of crystalline hydrates Fe 2 (SO 4) 3 n H 2 O, where n= 12, 10, 9, 7, 6, 3. The most studied crystal hydrate is iron(III) sulfate nonahydrate Fe 2 (SO 4) 3 9H 2 O - yellow hexagonal crystals, unit cell parameters a= 1.085 nm, c= 1.703 nm, Z = 4. Easily soluble in water (440 g per 100 g of water) and ethanol, insoluble in acetone. In aqueous solutions, iron(III) sulfate acquires a red-brown color due to hydrolysis.

When heated, nonahydrate transforms at 98 °C into tetrahydrate, at 125 °C into monohydrate and at 175 °C into anhydrous Fe 2 (SO 4) 3, which above 600 °C decomposes into Fe 2 O 3 and SO 3.

2. Being in nature

A mineral containing mixed iron-aluminum sulfate is called mikasaite. mikasaite), With chemical formula(Fe 3+ , Al 3+) 2 (SO 4) 3 is the mineralogical form of iron(III) sulfate. This mineral carries the anhydrous form of ferrous sulfate and is therefore very rare in nature. Hydrated forms are most common, for example:

• Coquimbit (English) coquimbite) - Fe 2 (SO 4) 3 9H 2 O - nonahydrate - the most common among them.
• Parakokimbit (English) paracoquimbite) - nonahydrate - on the contrary, is the rarest mineral in nature.
• Cornelite (English) cornelite) - heptahydrate - and kuenstedtite (eng. quenstedtite) - decahydrate - are also rare.
• Lausenite (English) lausenite) - hexa- or pentahydrate, a little-studied mineral.

All of the natural iron hydrates listed above are fragile compounds and, when open, quickly erode.

2.1. Mars

Ferrous sulfate and jarosite were discovered by two Mars rovers: Spirit and Opportunity. These substances are a sign of strong oxidative conditions on the surface of Mars. In May 2009, the Spirit rover got stuck when it was driving through the planet's soft soil and struck iron sulfate deposits hidden under a layer of normal soil. Due to the fact that iron sulfate has a very low density, the rover was stuck so deep that part of its body touched the surface of the planet.

3. Receipt

In industry, iron(III) sulfate is obtained by calcining pyrite or marcasite with NaCl in air:

or dissolve iron(III) oxide in sulfuric acid:

In laboratory practice, iron(III) sulfate can be obtained from iron(III) hydroxide:

A preparation of the same purity can be obtained by oxidation of iron(II) sulfate with nitric acid:

oxidation can also be carried out with oxygen or sulfur oxide:

Concentrated sulfuric and nitric acid oxidize iron sulfide to iron(III) sulfate:

Iron disulfide can be oxidized with concentrated sulfuric acid:

Iron(II) ammonium sulfate (Mohr's salt) can also be oxidized with potassium dichromate. As a result of this reaction, four sulfates are released at once - iron(III), chromium(III), ammonia and potassium, and water:

Iron(III) sulfate can be obtained as one of the products thermal decomposition iron(II) sulfate:

Ferrates are reduced with dilute sulfuric acid to iron(III) sulfate:

Heating the pentahydrate to a temperature of 70-175 °C will obtain anhydrous iron(III) sulfate:

Iron(II) sulfate can be oxidized with an exotic oxidizing agent such as xenon(III) oxide:

4. Chemical properties

Iron(III) sulfate in aqueous solutions undergoes strong hydrolysis into the cation, and the solution turns reddish-brown:

Hot water or steam decompose iron(III) sulfate:

Anhydrous iron(III) sulfate decomposes when heated:

Alkali solutions decompose iron(III) sulfate; the reaction products depend on the concentration of the alkali:

If an equimolar solution of iron(III) and iron(II) sulfates reacts with alkali, the result is a complex iron oxide:

Active metals(such as magnesium, zinc, cadmium, iron) reduce iron(III) sulfate:

Some metal sulfides (eg copper, calcium, tin, lead, mercury) in aqueous solution reduce iron(III) sulfate:

WITH soluble salts orthophosphoric acid forms insoluble iron(III) phosphate (heterosite):

5.Usage

• As a reagent for hydrometallurgical processing of copper ores.
• As a coagulant in the treatment of wastewater, municipal and industrial wastewater.
• As a mordant for dyeing fabrics.
• When tanning leather.
• For pickling of stainless austenitic steels, gold and aluminum alloys.
• As a flotation regulator to reduce the buoyancy of ores.
• In medicine it is used as an astringent and hemostatic agent.
• IN chemical industry as an oxidizer and catalyst.

Length and distance converter Mass converter Bulk and food volume converter Area converter Volume and unit converter in culinary recipes Temperature Converter Pressure, Stress, Young's Modulus Converter Energy and Work Converter Power Converter Force Converter Time Converter Linear Velocity Converter Flat Angle Thermal Efficiency and Fuel Efficiency Converter Number Converter to various systems notations Converter of units of measurement of quantity of information Exchange rates Sizes of women's clothing and shoes Sizes of men's clothing and shoes Converter angular velocity and rotational speed Acceleration Converter Angular Acceleration Converter Density Converter Specific Volume Converter Moment of Inertia Converter Moment of Force Converter Torque Converter Converter specific heat Combustion (by mass) Converter of energy density and specific heat of combustion of fuel (by volume) Converter of temperature difference Converter of coefficient of thermal expansion Converter of thermal resistance Converter of specific thermal conductivity Converter specific heat capacity Energy exposure and thermal radiation power converter Heat flux density converter Heat transfer coefficient converter Volume flow rate converter Mass flow rate converter Molar flow rate converter Mass flow density converter Molar concentration converter Mass concentration in solution converter Dynamic (absolute) viscosity converter Kinematic viscosity converter Surface tension converter Vapor permeability converter Converter water vapor flux density Sound level converter Microphone sensitivity converter Sound pressure level (SPL) converter Sound pressure level converter with selectable reference pressure Brightness converter Luminous intensity converter Illuminance converter Computer graphics resolution converter Frequency and wavelength converter Optical power in diopters and focal length Optical Power in Diopters and Lens Magnification (×) Electrical Charge Converter Linear Charge Density Converter Surface Charge Density Converter Volume Charge Density Converter Converter electric current Linear current density converter Surface current density converter Voltage converter electric field Electrostatic Potential and Voltage Converter Converter electrical resistance Electrical resistivity converter Electrical conductivity converter Electrical conductivity converter Electrical capacity Inductance converter American wire gauge converter Levels in dBm (dBm or dBmW), dBV (dBV), watts and other units Magnetomotive force converter Voltage converter magnetic field Converter magnetic flux Magnetic induction converter Radiation. Absorbed dose rate converter ionizing radiation Radioactivity. Radioactive decay converter Radiation. Exposure dose converter Radiation. Absorbed Dose Converter Decimal Prefix Converter Data Transfer Typography and Imaging Unit Converter Timber Volume Unit Converter Molar Mass Calculation Periodic table chemical elements D. I. Mendeleev

Chemical formula

Molar mass of Fe 2 (SO 4) 3, iron (III) sulfate 399.8778 g/mol

55.845 2+(32.065+15.9994 4) 3

Mass fractions of elements in the compound

Using the Molar Mass Calculator

• Chemical formulas must be entered case sensitive
• Subscripts are entered as regular numbers
• The point on the middle line (multiplication sign), used, for example, in the formulas of crystalline hydrates, is replaced by a regular point.
• Example: instead of CuSO₄·5H₂O in the converter, for ease of entry, the spelling CuSO4.5H2O is used.

Molar mass calculator

Mole

All substances are made up of atoms and molecules. In chemistry, it is important to accurately measure the mass of substances that react and are produced as a result. By definition, the mole is the SI unit of quantity of a substance. One mole contains exactly 6.02214076×10²³ elementary particles. This value is numerically equal to Avogadro's constant N A when expressed in units of mol⁻¹ and is called Avogadro's number. Amount of substance (symbol n) of a system is a measure of the number of structural elements. A structural element can be an atom, molecule, ion, electron, or any particle or group of particles.

Avogadro's constant N A = 6.02214076×10²³ mol⁻¹. Avogadro's number is 6.02214076×10²³.

In other words, a mole is an amount of substance equal in mass to the sum of the atomic masses of atoms and molecules of the substance, multiplied by Avogadro's number. The unit of quantity of a substance, the mole, is one of the seven basic SI units and is symbolized by the mole. Since the name of the unit and its symbol are the same, it should be noted that the symbol is not declined, unlike the name of the unit, which can be declined according to the usual rules of the Russian language. One mole of pure carbon-12 is equal to exactly 12 g.

Molar mass

Molar mass - physical property of a substance, defined as the ratio of the mass of that substance to the amount of substance in moles. In other words, this is the mass of one mole of a substance. The SI unit of molar mass is kilogram/mol (kg/mol). However, chemists are accustomed to using the more convenient unit g/mol.

molar mass= g/mol

Molar mass of elements and compounds

Compounds are substances consisting of different atoms that are chemically bonded to each other. For example, the following substances, which can be found in any housewife’s kitchen, are chemical compounds:

• salt (sodium chloride) NaCl
• sugar (sucrose) C₁₂H₂₂O₁₁
• vinegar (acetic acid solution) CH₃COOH

The molar mass of a chemical element in grams per mole is numerically the same as the mass of the element's atoms expressed in atomic mass units (or daltons). The molar mass of compounds is equal to the sum of the molar masses of the elements that make up the compound, taking into account the number of atoms in the compound. For example, the molar mass of water (H₂O) is approximately 1 × 2 + 16 = 18 g/mol.

Molecular weight

Molecular mass (the old name is molecular weight) is the mass of a molecule, calculated as the sum of the masses of each atom that makes up the molecule, multiplied by the number of atoms in this molecule. Molecular weight is dimensionless physical quantity, numerically equal to the molar mass. That is, molecular mass differs from molar mass in dimension. Even though molecular mass is a dimensionless quantity, it still has a value called the atomic mass unit (amu) or dalton (Da), and approximately equal to mass one proton or neutron. The atomic mass unit is also numerically equal to 1 g/mol.

Calculation of molar mass

Molar mass is calculated as follows:

• determine atomic masses elements according to the periodic table;
• determine the number of atoms of each element in the compound formula;
• determine the molar mass by adding the atomic masses of the elements included in the compound, multiplied by their number.

For example, let's calculate the molar mass of acetic acid

It consists of:

• two carbon atoms
• four hydrogen atoms
• two oxygen atoms

• carbon C = 2 × 12.0107 g/mol = 24.0214 g/mol
• hydrogen H = 4 × 1.00794 g/mol = 4.03176 g/mol
• oxygen O = 2 × 15.9994 g/mol = 31.9988 g/mol
• molar mass = 24.0214 + 4.03176 + 31.9988 = 60.05196 g/mol

Our calculator performs exactly this calculation. You can enter the acetic acid formula into it and check what happens.

Do you find it difficult to translate units of measurement from one language to another? Colleagues are ready to help you. Post a question in TCTerms and within a few minutes you will receive an answer.