🧪 Chemistry Overview
Exploring the fascinating world of chemical sciences and matter
1.1 What is Chemistry?
Chemistry is the branch of science which deals with the properties, composition and the structure of substances. It also deals with the physical and chemical changes that matter may undergo. Chemistry studies the principles which govern these changes.
Determination of composition represents finding out percentages of elements and compounds in a sample of matter. Structure of matter means the arrangement of atoms in matter, both physical and chemical changes may be brought about by absorption or evolution of energy.
🔬 Branches of Chemistry
To understand the widely spread complex subjects of chemistry and to concentrate on its specific aspects, chemistry is divided into many distinct branches. These branches have distinct areas of study for the scientists to focus on and use different breakthrough and understanding.
1. Physical Chemistry
The branch which explains how substances behave at atomic and molecular levels. It provides clear explanation as to how fundamental physical laws governing energy, matter, electron and molecules, to show specific characteristics and in turn react to give huge structures related to life. Physical chemistry is also used to find and compute the rate of reactions and functions that can optimize to exert with reactions on industrial scale.
2. Inorganic Chemistry
It is the study of the synthesis, composition, properties and structure of elements and compounds that contain little or no carbon. An inorganic substance can be composed of metals, nonmetals or a mixture of these, salts, acids and bases. Inorganic compounds are used as fertilizers, medicines, catalysts, pigments, coatings and much more.
3. Organic Chemistry
It is the branch of chemistry that deals with the carbon compounds that we see in our carbon-containing compound chemistry compounds such as carbonates, oxides and carbides. In this branch, we study the structure, formation, properties, composition and reactions of carbon containing compounds. Organic compounds are found in all forms of life and are also essential for life.
4. Environmental Chemistry
It is the scientific study of the chemical and biochemical phenomena that occur in this planet. In this subject, we study the sources, reactions, effects and fates of chemical species in the air, soil and water environments. Without this, it would be impossible to study the effects that humans have on the environment through the release of chemicals. It helps in understanding the causes, effects and solutions of different types of pollution.
5. Analytical Chemistry
This branch of chemistry deals with the analysis of different substances. It involves separation, identification and determination of the quantities of the components present in material things. Nowadays the field of analytical chemistry is generation involves the use and analytical sophisticated instruments to analyze the matter.
6. Biochemistry
It is the branch of chemistry in which we understand life through chemical processes. It is the study of chemical substances and vital processes occurring in living organisms. Biochemistry involves imaging into the structure and function of cellular components, such as proteins, carbohydrates, lipids, and nucleic acids.
7. Nuclear Chemistry
Nuclear chemistry deals with the reactions taking place in the nucleus of an atom. At levels in which we study whether nuclear processes include transmutation in the nuclei of atoms. Nuclear chemistry has many applications in agriculture, medicine, industry and research.
8. Polymer Chemistry
Polymers are large molecules made by linking together a series of building blocks. Polymer chemistry focuses on the properties, structure and synthesis of polymers and macromolecules. Many materials including living organisms including proteins, cellulose and nucleic acids are naturally occurring polymers.
9. Geochemistry
The study of chemical composition of earth and its sources and minerals is called geochemistry. Apart from its use in minerals exploration, geochemical mapping today has applications in environmental monitoring, forestry and medical investigation.
🌙 Interesting Information!
Geothermal heat pumps use a pump to transfer underground water into the buildings during the winter to heat them and in the summer to cool them.
🚀 Moon Mission Chemistry
A lunar mission has recently brought samples from the Moon. The following experiments were then carried out on it. Point out the branch of chemistry these experiments are related to:
- Determining its composition
- Studying the physical properties of materials it contains
- Carrying out chemical reactions with usual inorganic reagents
1.2 States of Matter
The study of matter is one of matter and energy. Energy is non-material in nature. Anything other than energy which carries weight and occupies volume is called matter. We encounter material things everywhere in all sorts of different situations.
A state of matter is one of the many distinct forms in which matter can exist. We observe four states of matter: solid, liquid, gas and plasma. Apart from these there are more states of matter which we do not see in everyday life.
🧊 Solid
The three primary states of matter are the solid, liquid and gaseous. They are different from each other due to different strength of intermolecular forces. The arrangement of particles and the distance between the particles Fig (1.1). In gases, molecules are very widely apart with no order whatsoever and very weak intermolecular forces. All these features make gases easily compressible and their densities are obviously very low.
💧 Liquid
The liquids also are fluid and have molecules which are closely attached but moving randomly. There exists significant intermolecular forces between their molecules. Liquids are not easily compressed and their densities are higher than those of gases.
💨 Gas
Solids have a definite shape and a fixed volume. Particles in solids are arranged in a regular and repeating pattern within the atomic structure. The particles in solids remain fixed at their positions where they can oscillate about their mean positions. Solids are relatively incompressible. The densities of solids are very high. Solids are the only state of matter which do not need any container or anything to be stored in crystalline solids are perfectly arranged and strongly bonded. This makes them almost incompressible.
⚡ Plasma
Plasma is not so generally seen form of matter. It is composed of particles with very high energy. It exists in fluorescent tubes, lightning and welding arcs. Plasma can be devised as a partially ionized gas containing electrons, ions positron, atoms and molecules.
🔬 Advanced States
There are some other intermediate states where liquid crystalline and some solid, for example supercritical fluids, liquid crystals and graphene. Supercritical fluids are highly compressed states which show both properties of gases and liquids. Chemical reactions which may not be carried out in conventional solvents may possibly be carried out in supercritical carbon dioxide.
🧪 Chemistry Overview
Exploring the fascinating world of chemical sciences and matter
1.1 What is Chemistry?
Chemistry is the branch of science which deals with the properties, composition and the structure of substances. It also deals with the physical and chemical changes that matter may undergo. Chemistry studies the principles which govern these changes.
Determination of composition represents finding out percentages of elements and compounds in a sample of matter. Structure of matter means the arrangement of atoms in matter, both physical and chemical changes may be brought about by absorption or evolution of energy.
🔬 Branches of Chemistry
To understand the widely spread complex subjects of chemistry and to concentrate on its specific aspects, chemistry is divided into many distinct branches. These branches have distinct areas of study for the scientists to focus on and use different breakthrough and understanding.
1. Physical Chemistry
The branch which explains how substances behave at atomic and molecular levels. It provides clear explanation as to how fundamental physical laws governing energy, matter, electron and molecules, to show specific characteristics and in turn react to give huge structures related to life. Physical chemistry is also used to find and compute the rate of reactions and functions that can optimize to exert with reactions on industrial scale.
2. Inorganic Chemistry
It is the study of the synthesis, composition, properties and structure of elements and compounds that contain little or no carbon. An inorganic substance can be composed of metals, nonmetals or a mixture of these, salts, acids and bases. Inorganic compounds are used as fertilizers, medicines, catalysts, pigments, coatings and much more.
3. Organic Chemistry
It is the branch of chemistry that deals with the carbon compounds that we see in our carbon-containing compound chemistry compounds such as carbonates, oxides and carbides. In this branch, we study the structure, formation, properties, composition and reactions of carbon containing compounds. Organic compounds are found in all forms of life and are also essential for life.
4. Environmental Chemistry
It is the scientific study of the chemical and biochemical phenomena that occur in this planet. In this subject, we study the sources, reactions, effects and fates of chemical species in the air, soil and water environments. Without this, it would be impossible to study the effects that humans have on the environment through the release of chemicals. It helps in understanding the causes, effects and solutions of different types of pollution.
5. Analytical Chemistry
This branch of chemistry deals with the analysis of different substances. It involves separation, identification and determination of the quantities of the components present in material things. Nowadays the field of analytical chemistry is generation involves the use and analytical sophisticated instruments to analyze the matter.
6. Biochemistry
It is the branch of chemistry in which we understand life through chemical processes. It is the study of chemical substances and vital processes occurring in living organisms. Biochemistry involves imaging into the structure and function of cellular components, such as proteins, carbohydrates, lipids, and nucleic acids.
7. Nuclear Chemistry
Nuclear chemistry deals with the reactions taking place in the nucleus of an atom. At levels in which we study whether nuclear processes include transmutation in the nuclei of atoms. Nuclear chemistry has many applications in agriculture, medicine, industry and research.
8. Polymer Chemistry
Polymers are large molecules made by linking together a series of building blocks. Polymer chemistry focuses on the properties, structure and synthesis of polymers and macromolecules. Many materials including living organisms including proteins, cellulose and nucleic acids are naturally occurring polymers.
9. Geochemistry
The study of chemical composition of earth and its sources and minerals is called geochemistry. Apart from its use in minerals exploration, geochemical mapping today has applications in environmental monitoring, forestry and medical investigation.
🌙 Interesting Information!
Geothermal heat pumps use a pump to transfer underground water into the buildings during the winter to heat them and in the summer to cool them.
🚀 Moon Mission Chemistry
A lunar mission has recently brought samples from the Moon. The following experiments were then carried out on it. Point out the branch of chemistry these experiments are related to:
- Determining its composition
- Studying the physical properties of materials it contains
- Carrying out chemical reactions with usual inorganic reagents
1.2 States of Matter
The study of matter is one of matter and energy. Energy is non-material in nature. Anything other than energy which carries weight and occupies volume is called matter. We encounter material things everywhere in all sorts of different situations.
A state of matter is one of the many distinct forms in which matter can exist. We observe four states of matter: solid, liquid, gas and plasma. Apart from these there are more states of matter which we do not see in everyday life.
🧊 Solid
The three primary states of matter are the solid, liquid and gaseous. They are different from each other due to different strength of intermolecular forces. The arrangement of particles and the distance between the particles Fig (1.1). In gases, molecules are very widely apart with no order whatsoever and very weak intermolecular forces. All these features make gases easily compressible and their densities are obviously very low.
💧 Liquid
The liquids also are fluid and have molecules which are closely attached but moving randomly. There exists significant intermolecular forces between their molecules. Liquids are not easily compressed and their densities are higher than those of gases.
💨 Gas
Solids have a definite shape and a fixed volume. Particles in solids are arranged in a regular and repeating pattern within the atomic structure. The particles in solids remain fixed at their positions where they can oscillate about their mean positions. Solids are relatively incompressible. The densities of solids are very high. Solids are the only state of matter which do not need any container or anything to be stored in crystalline solids are perfectly arranged and strongly bonded. This makes them almost incompressible.
⚡ Plasma
Plasma is not so generally seen form of matter. It is composed of particles with very high energy. It exists in fluorescent tubes, lightning and welding arcs. Plasma can be devised as a partially ionized gas containing electrons, ions positron, atoms and molecules.
🔬 Advanced States
There are some other intermediate states where liquid crystalline and some solid, for example supercritical fluids, liquid crystals and graphene. Supercritical fluids are highly compressed states which show both properties of gases and liquids. Chemical reactions which may not be carried out in conventional solvents may possibly be carried out in supercritical carbon dioxide.
1.3 Element, Compound and Mixture
Matter is the basis for the formation of elements, compounds and mixtures. Element is the simplest form of matter. It is a pure substance containing the same kind of atoms. It cannot be broken down into simpler substances by ordinary chemical reactions. Elements exist in all three forms: solid, liquid and gas. Most of the elements found in this world exist in solid form. Liquid and gaseous elements are very few in numbers compared to solids.
⚛️ Elements
Elements may be a metal, a non-metal, a metalloid and a noble gas. Elements can also be isotopes of carbon, hydrogen and oxygen. Some examples of elements are sodium, potassium, magnesium, calcium, carbon, silicon, nitrogen, oxygen, chlorine, helium, copper, gold, zinc, silver, nickel, cobalt, chromium, vanadium, etc.
🧪 Compounds
Compound is also a pure substance. It is made up of two or more different elements, chemically combined in a fixed ratio. When elements combine, they react with each other and form chemical bonds that are not easy to break. Examples of important compounds are water, ammonia, methane, carbon dioxide, sodium carbonate, potassium chloride, starch, proteins, carbohydrates, mineral acids, organic acids etc.
🔬 Mixtures
The composition and properties of an element or a compound are uniform throughout when we take one sample to another. A mixture is formed when more than one types of elements or compounds are mixed together in any ratio. Air, soil, milk and tea are everyday examples of mixtures. A mixture may be homogeneous or heterogeneous. A solution of salt in water is an example of a homogeneous mixture.
1.4 Allotropic Forms of Substances
Elements may exist in more than one structural forms which can exhibit quite different physical and chemical properties. These forms are called allotropic forms and phenomenon is called allotropy. Element oxygen exists in two allotropic forms namely oxygen (O₂) and ozone (O₃).
💎 Carbon Allotropes
Similarly, carbon has three main allotropic forms namely graphite, diamond and Buckminster fullerene. Diamond has a giant macromolecular structure of hexagonal structure of hexagonal rings of carbon. Buckminster fullerene (C₆₀) consists of spheres made of atoms arranged in pentagons and hexagons. Fullerene are stable at high temperatures and high pressures. Being covalent in nature, they are soluble in organic solvents. The fullerene structure is unique in that the molecule is not charged, has no boundaries and has no unpaired electrons. They have a cage like structure. Fullerene C₇₀ has a low melting point, it is soft and cannot conduct electricity. Element sulphur also exists in two crystalline allotropic forms i.e. rhombic and monoclinic. Its forme is more stable than the latter.
📊 Graphite
Layered structure, conducts electricity, soft and slippery
💎 Diamond
3D network structure, hardest natural substance, brilliant
⚽ Buckminsterfullerene
Spherical cage-like structure, C₆₀ molecular formula
🟡 Sulphur Forms
Rhombic (stable) and Monoclinic (less stable) crystalline forms
1.7 Formation of Unsaturated and Saturated Solutions
Take about 100g of water in a beaker, and add to kg of table sugar, and stir it. The sugar will dissolve in water. Then add another 5g of sugar and stir. This will also dissolve. This solution is called an unsaturated solution. A solution which can dissolve more amount of a solute at a particular temperature is called an unsaturated solution. Keep on adding sugar little by little. As the total quantity of sugar in water increases, its dissolution will become more difficult. A stage comes when no more sugar will dissolve in water at this temperature. Any more sugar added at this stage will settle down at the bottom of the beaker. This solution is called a saturated solution at a particular temperature.
🔬 Solution Types
A solution in which the maximum amount of the solute has been dissolved in a particular amount of a solvent at a particular temperature is called a saturated solution.
Different compounds have different solubilities in a particular solvent. For example, if the solutions of basic sugar and sodium chloride are prepared, it is found that 150g of sugar can dissolve in 100g of water at 20°C but only 30g sodium chloride dissolve in the same amount of water at the same temperature.
1.8 Effect of Temperature on the Solubility of Solutes
The solubility of a solute is the amount of solute which can dissolve in 100g of a solvent at a particular temperature.
Change in temperature has different effects on the solubility of different compounds. Usually the solubility increases with the increase in temperature but it cannot be taken as a general rule. There are a large number of compounds whose solubility in water increases with the increase in temperature e.g. potassium nitrate (KNO₃), silver nitrate (AgNO₃) and potassium chloride (KCl) etc.
📈 Increasing Solubility
Most ionic compounds like lithium carbonate (Li₂CO₃), calcium chromate or green vitriol (CaCrO₄) decreases with the increase in temperature. The solubility of gases in water also decrease with the increase in temperature.
📉 Decreasing Solubility
Similarly, the solubilities of CaO, sulphate and sodium nitrate also increase with increase in the temperature. However, the solubility of calcium hydroxide Ca(OH)₂ decrease in temperature.
🧪 Laboratory Activity
Saturated Solution Preparation:
Take 100g of water in a beaker and prepare saturated solution of sugar at room temperature. Heat the beaker on a spirit lamp. Add a little more sugar in it and stir it. Will this sugar be dissolved in it? You will observe that with the increase in temperature, the quantity of sugar dissolved in water has increased i.e. the solubility of sugar has increased.
🤔 Exercise Question
How variation of solubility at different temperatures can be useful for us?
💡 Interesting Information!
Mixtures are closely related to our everyday lives. The air we breathe, the food we generally consume, the soil of our farm on field, our body, the solids like ice we see, are all either homogeneous or heterogeneous mixtures.
🧪 Chemistry Overview
Exploring the fascinating world of chemical sciences and matter
1.1 What is Chemistry?
Chemistry is the branch of science which deals with the properties, composition and the structure of substances. It also deals with the physical and chemical changes that matter may undergo. Chemistry studies the principles which govern these changes.
Determination of composition represents finding out percentages of elements and compounds in a sample of matter. Structure of matter means the arrangement of atoms in matter, both physical and chemical changes may be brought about by absorption or evolution of energy.
🔬 Branches of Chemistry
To understand the widely spread complex subjects of chemistry and to concentrate on its specific aspects, chemistry is divided into many distinct branches. These branches have distinct areas of study for the scientists to focus on and use different breakthrough and understanding.
1. Physical Chemistry
The branch which explains how substances behave at atomic and molecular levels. It provides clear explanation as to how fundamental physical laws governing energy, matter, electron and molecules, to show specific characteristics and in turn react to give huge structures related to life. Physical chemistry is also used to find and compute the rate of reactions and functions that can optimize to exert with reactions on industrial scale.
2. Inorganic Chemistry
It is the study of the synthesis, composition, properties and structure of elements and compounds that contain little or no carbon. An inorganic substance can be composed of metals, nonmetals or a mixture of these, salts, acids and bases. Inorganic compounds are used as fertilizers, medicines, catalysts, pigments, coatings and much more.
3. Organic Chemistry
It is the branch of chemistry that deals with the carbon compounds that we see in our carbon-containing compound chemistry compounds such as carbonates, oxides and carbides. In this branch, we study the structure, formation, properties, composition and reactions of carbon containing compounds. Organic compounds are found in all forms of life and are also essential for life.
4. Environmental Chemistry
It is the scientific study of the chemical and biochemical phenomena that occur in this planet. In this subject, we study the sources, reactions, effects and fates of chemical species in the air, soil and water environments. Without this, it would be impossible to study the effects that humans have on the environment through the release of chemicals. It helps in understanding the causes, effects and solutions of different types of pollution.
5. Analytical Chemistry
This branch of chemistry deals with the analysis of different substances. It involves separation, identification and determination of the quantities of the components present in material things. Nowadays the field of analytical chemistry is generation involves the use and analytical sophisticated instruments to analyze the matter.
6. Biochemistry
It is the branch of chemistry in which we understand life through chemical processes. It is the study of chemical substances and vital processes occurring in living organisms. Biochemistry involves imaging into the structure and function of cellular components, such as proteins, carbohydrates, lipids, and nucleic acids.
7. Nuclear Chemistry
Nuclear chemistry deals with the reactions taking place in the nucleus of an atom. At levels in which we study whether nuclear processes include transmutation in the nuclei of atoms. Nuclear chemistry has many applications in agriculture, medicine, industry and research.
8. Polymer Chemistry
Polymers are large molecules made by linking together a series of building blocks. Polymer chemistry focuses on the properties, structure and synthesis of polymers and macromolecules. Many materials including living organisms including proteins, cellulose and nucleic acids are naturally occurring polymers.
9. Geochemistry
The study of chemical composition of earth and its sources and minerals is called geochemistry. Apart from its use in minerals exploration, geochemical mapping today has applications in environmental monitoring, forestry and medical investigation.
🌙 Interesting Information!
Geothermal heat pumps use a pump to transfer underground water into the buildings during the winter to heat them and in the summer to cool them.
🚀 Moon Mission Chemistry
A lunar mission has recently brought samples from the Moon. The following experiments were then carried out on it. Point out the branch of chemistry these experiments are related to:
- Determining its composition
- Studying the physical properties of materials it contains
- Carrying out chemical reactions with usual inorganic reagents
1.2 States of Matter
The study of matter is one of matter and energy. Energy is non-material in nature. Anything other than energy which carries weight and occupies volume is called matter. We encounter material things everywhere in all sorts of different situations.
A state of matter is one of the many distinct forms in which matter can exist. We observe four states of matter: solid, liquid, gas and plasma. Apart from these there are more states of matter which we do not see in everyday life.
🧊 Solid
The three primary states of matter are the solid, liquid and gaseous. They are different from each other due to different strength of intermolecular forces. The arrangement of particles and the distance between the particles Fig (1.1). In gases, molecules are very widely apart with no order whatsoever and very weak intermolecular forces. All these features make gases easily compressible and their densities are obviously very low.
💧 Liquid
The liquids also are fluid and have molecules which are closely attached but moving randomly. There exists significant intermolecular forces between their molecules. Liquids are not easily compressed and their densities are higher than those of gases.
💨 Gas
Solids have a definite shape and a fixed volume. Particles in solids are arranged in a regular and repeating pattern within the atomic structure. The particles in solids remain fixed at their positions where they can oscillate about their mean positions. Solids are relatively incompressible. The densities of solids are very high. Solids are the only state of matter which do not need any container or anything to be stored in crystalline solids are perfectly arranged and strongly bonded. This makes them almost incompressible.
⚡ Plasma
Plasma is not so generally seen form of matter. It is composed of particles with very high energy. It exists in fluorescent tubes, lightning and welding arcs. Plasma can be devised as a partially ionized gas containing electrons, ions positron, atoms and molecules.
🔬 Advanced States
There are some other intermediate states where liquid crystalline and some solid, for example supercritical fluids, liquid crystals and graphene. Supercritical fluids are highly compressed states which show both properties of gases and liquids. Chemical reactions which may not be carried out in conventional solvents may possibly be carried out in supercritical carbon dioxide.
1.3 Element, Compound and Mixture
Matter is the basis for the formation of elements, compounds and mixtures. Element is the simplest form of matter. It is a pure substance containing the same kind of atoms. It cannot be broken down into simpler substances by ordinary chemical reactions. Elements exist in all three forms: solid, liquid and gas. Most of the elements found in this world exist in solid form. Liquid and gaseous elements are very few in numbers compared to solids.
⚛️ Elements
Elements may be a metal, a non-metal, a metalloid and a noble gas. Elements can also be isotopes of carbon, hydrogen and oxygen. Some examples of elements are sodium, potassium, magnesium, calcium, carbon, silicon, nitrogen, oxygen, chlorine, helium, copper, gold, zinc, silver, nickel, cobalt, chromium, vanadium, etc.
🧪 Compounds
Compound is also a pure substance. It is made up of two or more different elements, chemically combined in a fixed ratio. When elements combine, they react with each other and form chemical bonds that are not easy to break. Examples of important compounds are water, ammonia, methane, carbon dioxide, sodium carbonate, potassium chloride, starch, proteins, carbohydrates, mineral acids, organic acids etc.
🔬 Mixtures
The composition and properties of an element or a compound are uniform throughout when we take one sample to another. A mixture is formed when more than one types of elements or compounds are mixed together in any ratio. Air, soil, milk and tea are everyday examples of mixtures. A mixture may be homogeneous or heterogeneous. A solution of salt in water is an example of a homogeneous mixture.
1.4 Allotropic Forms of Substances
Elements may exist in more than one structural forms which can exhibit quite different physical and chemical properties. These forms are called allotropic forms and phenomenon is called allotropy. Element oxygen exists in two allotropic forms namely oxygen (O₂) and ozone (O₃).
💎 Carbon Allotropes
Similarly, carbon has three main allotropic forms namely graphite, diamond and Buckminster fullerene. Diamond has a giant macromolecular structure of hexagonal structure of hexagonal rings of carbon. Buckminster fullerene (C₆₀) consists of spheres made of atoms arranged in pentagons and hexagons. Fullerene are stable at high temperatures and high pressures. Being covalent in nature, they are soluble in organic solvents. The fullerene structure is unique in that the molecule is not charged, has no boundaries and has no unpaired electrons. They have a cage like structure. Fullerene C₇₀ has a low melting point, it is soft and cannot conduct electricity. Element sulphur also exists in two crystalline allotropic forms i.e. rhombic and monoclinic. Its forme is more stable than the latter.
📊 Graphite
Layered structure, conducts electricity, soft and slippery
💎 Diamond
3D network structure, hardest natural substance, brilliant
⚽ Buckminsterfullerene
Spherical cage-like structure, C₆₀ molecular formula
🟡 Sulphur Forms
Rhombic (stable) and Monoclinic (less stable) crystalline forms
1.7 Formation of Unsaturated and Saturated Solutions
Take about 100g of water in a beaker, and add to kg of table sugar, and stir it. The sugar will dissolve in water. Then add another 5g of sugar and stir. This will also dissolve. This solution is called an unsaturated solution. A solution which can dissolve more amount of a solute at a particular temperature is called an unsaturated solution. Keep on adding sugar little by little. As the total quantity of sugar in water increases, its dissolution will become more difficult. A stage comes when no more sugar will dissolve in water at this temperature. Any more sugar added at this stage will settle down at the bottom of the beaker. This solution is called a saturated solution at a particular temperature.
🔬 Solution Types
A solution in which the maximum amount of the solute has been dissolved in a particular amount of a solvent at a particular temperature is called a saturated solution.
Different compounds have different solubilities in a particular solvent. For example, if the solutions of basic sugar and sodium chloride are prepared, it is found that 150g of sugar can dissolve in 100g of water at 20°C but only 30g sodium chloride dissolve in the same amount of water at the same temperature.
1.8 Effect of Temperature on the Solubility of Solutes
The solubility of a solute is the amount of solute which can dissolve in 100g of a solvent at a particular temperature.
Change in temperature has different effects on the solubility of different compounds. Usually the solubility increases with the increase in temperature but it cannot be taken as a general rule. There are a large number of compounds whose solubility in water increases with the increase in temperature e.g. potassium nitrate (KNO₃), silver nitrate (AgNO₃) and potassium chloride (KCl) etc.
📈 Increasing Solubility
Most ionic compounds like lithium carbonate (Li₂CO₃), calcium chromate or green vitriol (CaCrO₄) decreases with the increase in temperature. The solubility of gases in water also decrease with the increase in temperature.
📉 Decreasing Solubility
Similarly, the solubilities of CaO, sulphate and sodium nitrate also increase with increase in the temperature. However, the solubility of calcium hydroxide Ca(OH)₂ decrease in temperature.
🧪 Laboratory Activity
Saturated Solution Preparation:
Take 100g of water in a beaker and prepare saturated solution of sugar at room temperature. Heat the beaker on a spirit lamp. Add a little more sugar in it and stir it. Will this sugar be dissolved in it? You will observe that with the increase in temperature, the quantity of sugar dissolved in water has increased i.e. the solubility of sugar has increased.
🤔 Exercise Question
How variation of solubility at different temperatures can be useful for us?
💡 Interesting Information!
Mixtures are closely related to our everyday lives. The air we breathe, the food we generally consume, the soil of our farm on field, our body, the solids like ice we see, are all either homogeneous or heterogeneous mixtures.
