Easiest biomolecule Notes12th class Cbse

detailed note on the chapter "Biomolecules" in Class 12 Chemistry:

Introduction: Biomolecules are the molecules that are involved in the maintenance and metabolic processes of living organisms. Biomolecules can be broadly classified into four types: carbohydrates, proteins, lipids, and nucleic acids. Carbohydrates: Carbohydrates are the most abundant biomolecules on Earth, and they are essential for providing energy to the body. Carbohydrates are classified into monosaccharides, disaccharides, and polysaccharides based on their structure. Monosaccharides, such as glucose and fructose, are the simplest carbohydrates and cannot be hydrolyzed into smaller sugars. Disaccharides, such as sucrose and lactose, are formed by the condensation of two monosaccharides. Polysaccharides, such as starch and cellulose, are formed by the condensation of many monosaccharide units. Proteins: Proteins are large biomolecules that are involved in various cellular processes, including structural support, enzymatic catalysis, and transport. Proteins are composed of amino acid monomers that are linked together by peptide bonds. Proteins are classified into four levels of structure: primary, secondary, tertiary, and quaternary. Lipids: Lipids are a diverse group of biomolecules that are insoluble in water. Lipids are classified into four types: fatty acids, triglycerides, phospholipids, and steroids. Fatty acids are the building blocks of most lipids and are composed of a carboxylic acid group attached to a hydrocarbon chain. Triglycerides are formed by the esterification of three fatty acids with a glycerol molecule. Phospholipids are composed of a polar head group and two fatty acid tails and are the main component of cell membranes. Steroids, such as cholesterol and hormones, are composed of a four-ring structure and have various physiological functions. Nucleic Acids: Nucleic acids are biomolecules that store and transmit genetic information. Nucleic acids are composed of nucleotide monomers that are linked together by phosphodiester bonds. Nucleic acids are classified into two types: deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). DNA is composed of a double helix structure and stores genetic information, while RNA is involved in the synthesis of proteins. Conclusion: The chapter "Biomolecules" in Class 12 Chemistry covers the essential biomolecules carbohydrates, proteins, lipids, and nucleic acids. The knowledge of these biomolecules is crucial in understanding the biochemistry and metabolic processes in living organisms.

Easiest amines Notes12th class Cbse

"Amines" :

Introduction:

Amines are organic compounds that contain a nitrogen atom bonded to one or more alkyl or aryl groups. Amines are classified based on the number of alkyl or aryl groups bonded to the nitrogen atom: primary (1°), secondary (2°), or tertiary (3°). Amines have a wide range of applications, including as solvents, dyes, and pharmaceuticals.

Preparation of Amines:

1. Reduction of Nitro Compounds:

Amines can be prepared by reducing nitro compounds with reducing agents such as hydrogen gas (H2) or tin (Sn) and hydrochloric acid (HCl).

2. Reduction of Nitriles:

Amines can also be prepared by reducing nitriles with reducing agents such as lithium aluminum hydride (LiAlH4) or sodium borohydride (NaBH4).

3. Gabriel Synthesis:

Primary amines can be synthesized by the Gabriel synthesis, which involves the reaction of potassium phthalimide with an alkyl halide, followed by hydrolysis and decarboxylation.

4. Hoffmann Bromamide Reaction:

Amines can also be prepared by the Hoffmann bromamide reaction, which involves the reaction of a primary amide with bromine and sodium hydroxide (NaOH), followed by heating with a strong acid.

Properties of Amines:

1. Basicity:

Amines are basic in nature due to the lone pair of electrons on the nitrogen atom. The basicity of amines depends on the number of alkyl or aryl groups bonded to the nitrogen atom.

2. Solubility:

Amines are generally soluble in organic solvents, but their solubility in water decreases with increasing size of the alkyl or aryl groups.

3. Boiling Point:

The boiling points of amines increase with increasing size of the alkyl or aryl groups due to stronger intermolecular forces.

4. Alkylation and Acylation:

Amines can be alkylated or acylated to form secondary or tertiary amines. The reaction involves the replacement of one of the hydrogen atoms bonded to the nitrogen atom with an alkyl or acyl group.

Reactions of Amines:

1. Reaction with Acids:

Amines react with acids to form salts. The salts are soluble in water and are often used in the preparation of pharmaceuticals.

2. Reaction with Nitrous Acid:

Primary amines react with nitrous acid (HNO2) to form nitrosoamines, which are used in the production of dyes.

3. Reaction with Carbonyl Compounds:

Amines can react with carbonyl compounds, such as aldehydes and ketones, to form imines. The reaction is known as the Schiff base reaction and is used in the synthesis of pharmaceuticals.

4. Reaction with Haloalkanes:

Amines can react with haloalkanes to form secondary and tertiary amines. The reaction is known as the alkylation reaction and is used in the synthesis of pharmaceuticals.

In conclusion, the chapter "Amines" in Class 12 Chemistry covers the preparation, properties, and reactions of amines. Understanding the chemistry of amines is important in many fields, including pharmaceuticals, dyes, and organic solvents

class 12th chemistry chapter solution

            12th chemistry chapter solution 

I. Introduction to Solutions

• A solution is a homogeneous mixture of two or more substances.
• Solvent is the component present in the largest amount, while the solute is the other component(s).

II. Types of Solutions

• Unsaturated solutions have not reached the maximum amount of solute that can be dissolved in a solvent.
• Saturated solutions have the maximum amount of solute dissolved in a solvent at a given temperature and pressure.
• Supersaturated solutions contain more solute than the solvent can normally dissolve at a given temperature and pressure.

III. Concentration of Solutions

• Molarity is the number of moles of solute per liter of solution.
• Molality is the number of moles of solute per kilogram of solvent.
• Percent composition is the mass of solute per 100 grams of solution.
• Parts per million (ppm) is the number of parts of solute per million parts of solution.

IV. Colligative Properties of Solutions

• Colligative properties depend on the number of solute particles in solution, not their identity.
• Examples of colligative properties include lowering of vapor pressure, elevation of boiling point, depression of freezing point, and osmotic pressure.

V. Laws Governing Solutions

• Raoult's law states that the vapor pressure of a solution is proportional to the mole fraction of the solvent in the solution.
• Henry's law states that the solubility of a gas in a liquid is proportional to the partial pressure of the gas above the liquid.

VI. Osmosis and Reverse Osmosis

• Osmosis is the movement of solvent molecules from a region of lower solute concentration to a region of higher solute concentration through a semipermeable membrane.
• Reverse osmosis is the process of applying pressure to overcome osmotic pressure and move solvent molecules from a region of higher solute concentration to a region of lower solute concentration through a semipermeable membrane.

VII. Dialysis

• Dialysis is the process of separating solutes based on their size and charge using a semipermeable membrane.

VIII. Colloids

• Colloids are heterogeneous mixtures with particles intermediate in size between a solution and a suspension.
• Examples of colloids include emulsions, foams, and gels.

                                 Formulas

I. Concentration Formulas:

• Molarity (M) = moles of solute / liters of solution
• Molality (m) = moles of solute / kilograms of solvent
• Mass percentage = (mass of solute / mass of solution) x 100%
• Volume percentage = (volume of solute / volume of solution) x 100%
• Parts per million (ppm) = (mass of solute / mass of solution) x 10^6
• Parts per billion (ppb) = (mass of solute / mass of solution) x 10^9

II. Raoult's Law Formula:

• Vapor pressure of solution (P) = mole fraction of solvent (Xsolvent) x vapor pressure of pure solvent (Psolvent)
• P = Xsolvent x Psolvent

III. Colligative Properties Formulas:

• Freezing point depression (ΔTf) = Kf x molality of solute
• Boiling point elevation (ΔTb) = Kb x molality of solute
• Osmotic pressure (Π) = MRT (where M is the molarity of the solute, R is the gas constant, and T is the temperature in Kelvin)
• Van't Hoff factor (i) = moles of particles in solution after dissociation / moles of solute dissolved

IV. Henry's Law Formula:

• Concentration of gas in solution (C) = kH x partial pressure of gas above solution (Pgas)

V. Solubility Product Formula:

• Solubility product constant (Ksp) = [A+]^m [B-]^n (where A and B are ions in a dissociation reaction, and m and n are their stoichiometric coefficients)