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Chemistry

Some Important Carbon Compounds -Ethanol and Ethanoic acid

ASSESSMENT – CLICK HERE Previous Year’s CBSE Board Questions -Some Important Carbon Compounds – Ethanol and Ethanoic acid   [googlepdf url=”https://freakgenie.com/wp-content/uploads/2019/02/carbon-compd-ethanol-and-ethanoic-acid.pdf” width=”100%” height=”2560″] ASSESSMENT – CLICK HERE Previous Year’s CBSE Board Questions -Some Important Carbon Compounds – Ethanol and Ethanoic acid

Previous Year’s CBSE Board Questions -Some Important Carbon Compounds – Ethanol and Ethanoic acid

Some Important Carbon Compounds – Ethanol and Ethanoic acid 1. Write the name and molecular formula of an organic compound having its name suffixed with ‘-ol’ and having two carbon atoms in its molecule. Write balanced chemical equation to indicate what happens when it is heated with excess of conc. H2S04 and the name of …

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Common Behaviour of Acids and Bases

In the following section, we will find the answers of  following questions- (i) All acids have similar chemical properties. All bases have similar chemical properties. What   lead to this similarity in properties? (ii) How acids and bases are different chemically?        Group A                                                  Group B ACIDS                                                   BASES                                             Hydrochloric acid (HCl)                      Sodium hydroxide …

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Importance and Limitations of Modern Periodic Table

Importance of Modern Periodic Table 1. Based on atomic number –     The arrangement of elements in modern periodic table is according to their increasing order of atomic number. Atomic number increases by 1 unit (not fractional) in going from one element to the next element and equal to the number of electrons. Thus, the …

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Arrangements in Modern Periodic Table    (Long Form of Periodic Table)    

 The arrangement  in periodic table is given by Bohr so it is also known as Bohr’s table or Long form of periodic table. This table is prepared on the basis of – (a) increasing order of atomic number or electronic configuration. (placed in a period) (b) same number of valence electron/electrons. (placed in one group) …

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INTRODUCTION TO MODERN PERIODIC TABLE

The modern periodic table of elements is based on Mendeleev’s observations. The only difference is instead of being organized by atomic masses, the modern table is arranged by atomic number (Z). Henry Moseley, in 1913, found that atomic number is more fundamental property of an element than its atomic mass. Atomic number helps in arranging …

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Introduction to Organic Chemistry and Vital Force Theory

     ♦      Earth crust has only 0.02% carbon in the form of minerals (e.g. – carbonates, bicarbonates, coal, petroleum etc.) and atmosphere has 0.03% carbon dioxide. Inspite of its availability in such a small amount, it is highly important for our lives.                                                               ♦     Except water most of …

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WHAT IS FORMULA UNIT MASS OR FORMULA MASS?

The compounds which are formed by ions are called ionic compounds. In general, cations are made by metals and anions are made by non-metals. So, it can be understood as compounds made by metals and non-metals are ionic compounds. Examples – Al2(SO4)3, CaCl2, K2SO4, KNO3, CaCO3, NaCl, MgCl2 etc. Read more – Law of Conservation of …

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How do you Write Chemical Formula for an Ionic Compound?

Rules for writing a chemical formula  Write down the symbols of the ions (cation and anion) involved. Write the symbol of cation first (L.H.S) followed by the symbol of anion (R.H.S.). Write the valency of each ion. Interchange the valencies of the ions and write as the subscript. Write them close together and ignore ‘1’ …

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RULES FOR WRITING A CHEMICAL FORMULA OF SIMPLE COMPOUNDS

Chemical formula is a symbolic representation of a molecule’s composition. It indicates – (a) the elements that are present in the compound and (b) the ratio of these elements in the compound. A chemical formula is also called molecular formula. The symbols in the molecular formula tell us about the elements and the subscript tells …

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Problems / Numericals based on Mole Concept (Atomic Mass/ Molar Mass/ Avogadro number)

Formulas in brief –               Mass = Molar mass x Number of moles  Number of moles = Given number of particles / Avogadro number      Number of particles = (Given mass / molar mass) x Avogadro number          (from 1 and 2)  If one carbon atom has a mass of 12 atomic mass units and one magnesium atom has …

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Mole Concept – Introduction, Importance and Formulae

Introduction  The structure of matter can be one of the following – atoms → molecules → bulk compound or element atoms → bulk element atoms → ions → bulk ionic compound It clearly shows that the masses that are measured in the laboratory are masses corresponding to large numbers of tiny atoms or molecules. Logically …

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Importance of Mendeleev’s Periodic Table

Read First – Mendeleev’s Periodic Table (1) Systematic Study of the elements Mendeleev’s periodic table was developed in accordance to- (a) increasing atomic masses. (b) grouping of similar elements together. By the way, the study of elements became quite simpler, as if properties of one element in a particular group were known, properties of others …

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DISCOVERY OF CHARGED PARTICLES IN MATTER – Electron, Proton and Neutron

Read – Structure of the Atom / Inside the Atom – Summary Discovery of Electron – During 1890s’ many scientists performed experiments using cathode ray tubes.  A cathode ray tube or discharge tube is made of glass from which most of the air has been removed. Such a cathode ray tube can be seen in figure.  …

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Mendeleev’s Periodic Table

Read first – Periodic Classification of Elements – Inroduction, Dobereiner’s Traids Newlands’ Law of Octaves A most important contribution on arrangement of elements after Newland was given by a Russian Chemist called Dmitri Mendeleev. Before discussing Mendeleev’s periodic table, we should learn the meaning of following terms – Periodic Table –  It is a chart …

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What is the Versatile Nature of Carbon?

Why are carbon and its compounds so important or special from compounds of all the other more than hundred – odd elements of the periodic table?                   This is because – (a) The number of compounds that contain carbon is many time greater (due to catenation) than the  number of compounds that do not contain carbon. …

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Physical Properties of Non-Metals

Read First- Physical Properties of Metals Non-metals Physical state – Non-metals exists in all three physical state. Carbon, sulphur, phos-phorous etc. are solids. Oxygen, nitrogen, chlorine etc. are gases whereas bromine is a liquid.  Lustre – Non- metals are non-lustrous substances.            Exception – Diamond, graphite (allotropes of carbon) and iodine are lustrous in appearance. Hardness …

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Structure of the Atom / Inside the Atom – Summary

Latest CBSE syllabus topics –                                                                                                          Structure of atom – Electrons, protons and neutrons ; Isotopes and Isobars. Latest Maharashtra SSC Board syllabus topics – Inside the atom – Historical background ; Rutherford’s scattering experiment ; Distribution of electrons in orbits ; Electronic configuration of elements ; Isotopes and their applications. Summary – E. Goldstein discovered …

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Atoms and Molecules / Counting Matter- Summary, Introduction

 Summary – ♦ Laws of  Chemical Combination – (a) Law of Conservation of Mass – Mass can neither be created nor be destroyed in a chemical reaction. (b) Law of Constant Proportions – In a chemical substance, the elements are always present in definite proportions by mass. ♦ Dalton’s atomic theory – All matter is composed …

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Newlands’ Law of Octaves

Read First – Dobereiner’s Traids Read More – CHEMISTRY – MATTER / ATOMS AND MOLECULES / STRUCTURE OF THE ATOM / CHEMICAL REACTIONS AND EQUATIONS / ACIDS, BASES AND SALTS / METALS AND NON-METALS / CARBON AND ITS COMPOUNDS / PERIODIC CLASSIFICATION OF ELEMENTS   After as Dobereiner’s Traids was ruled out, an English chemist J.A.R. Newlands observed similarities in physical and chemical properties of every …

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PERIODIC CLASSIFICATION OF ELEMENTS – Introduction, Dobereiner’s Triads

  INTRODUCTION Till 18th centuries, only 30 elements were known. By the year 1865, 63 elements were discovered. Till date , 118 elements have been discovered and many more may be known in future. Read More – CHEMISTRY – MATTER / ATOMS AND MOLECULES / STRUCTURE OF THE ATOM / CHEMICAL REACTIONS AND EQUATIONS / ACIDS, BASES AND SALTS / METALS AND NON-METALS / CARBON …

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Physical Properties of Metals

Elements are broadly classified on the basis of their physical and chemical properties-                                (a) Metals (b) Non-metals Besides metals and non-metals, there is a third group of elements called metalloids which show properties intermediate to metals and non-metals. E.g.- silicon (Si), germanium (Ge), arsenic (As), antimony (Sb) and tellurium (Te). There are very few …

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Balancing of an Unbalanced Chemical Equation in 5 Easy Steps

Balancing of an unbalanced chemical equation means making the number of atoms of various elements equal in reactants and product in an equation. It is important to note that during balancing a reaction, the formula of a compound (or the subscript of the symbol) must not be changed. For e.g. – H2  +  O2  →  H2O Here, …

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How to write a Chemical Reaction in Chemical Equation Form?

The description of a chemical reaction in sentences is quite long and time consuming. To make it shorter, a chemical reaction can be written in word equation form. For e.g. – When a magnesium ribbon burns in air / oxygen, it gives magnesium oxide. Activity – 1  Word equation – Magnesium + Oxygen → Magnesium Oxide …

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Nature of Matter (on the basis of their Chemical Properties)

Read First – Can Matter change its States? States of Matter What is Matter? What is its Characteristics? [dropcap]Matter[/dropcap] is everything around us which is made up of tiny particles. In the previous posts, we have learnt classification of matter into solid, liquid and gas, on the basis of their physical properties. In the following post, …

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What is Matter? What are the Characteristics of Matter?

Matter is everything around you which is made up of particles. It has mass and occupies space. Mass is a physical quantity which expresses the amount of stuff in an object. The space inside the container that is occupied by matter is its volume. Early Indian philosophers classified matter in the form of five basic elements – the …

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What is Chemistry? What are the main branches? What is its Importance and Scope?

[dropcap]W[/dropcap]When you hear the word ‘chemistry,’ there are certain images that come to mind – a colorful lab, colored liquids, different smells – good or bad (Ugh!!), glass wares, test tubes, the periodic table, molecules, maybe even some cool explosions (BOOM!), magic tricks  in a movie…..But chemistry is so much more than these things… in fact, …

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A CHEMICAL REACTION IS CHARACTERIZED BY EVOLUTION OF A GAS AND BY EVOLVING HEAT (EXOTHERMIC REACTION).

Take a few zinc granules in a conical flask. Add dilute hydrochloric acid (HCl) or sulphuric acid (H2SO4) in the conical flask. (a) What do you observe ? (b) Touch the conical flask and observe any change in its temperature ? Objective – A chemical reaction characterized by evolution of a gas and by evolving heat …

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COMBINATION REACTION

Slowly add water in a small amount of calcium oxide or quick lime containing in a conical flask. Touch the beaker. Do you feel any change in temperature ? Objective – Combination reaction with heat change. Inference – Calcium oxide (CaO) reacts vigorously with water and form a single product, calcium hydroxide (slaked lime). CaO(s) + H2O …

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IN A CHEMICAL REACTION, ORIGINAL SUBSTANCE LOSES ITS NATURE AND IDENTITY

Objective– To understand a chemical reaction. Procedure – Take a magnesium ribbon. Clean it by rubbing with sand paper. (a) Why should magnesium ribbon be cleaned before burning in air ? Hold it with a pair of tongs. Burn it in the flame of a burner. Collect the ash so formed in a watch glass. Precaution …

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List of Polyatomic Ions and Charges

 Simple ions – The ions which are formed from single atom carrying a positive or negative charge are called simple ions or mono-atomic ions. Example – Na+, Cl–, O-2, Al+3, N-3(nitride), Mg+2, Ca+2, Cu+2, Fe+2etc. Polyatomic ions -Polyatomic ions or compound ions are molecules formed from groups of atoms bonded together that carry a positive …

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IONS – Anions and Cations

Atoms are neutral; they contain the same number of protons (positive particles) and electrons (negative particles). When the numbers of these subatomic particles are not equal, the atom is electrically charged and is called an ion i.e. ions are electrically charged atoms with extra electrons or missing electrons. It means ions are formed when atoms lose or gain …

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What is Matter?

Matter can be anything which occupy space and have mass. • On the basis of Physical state, matter can be divided into – (a) Solid (b) Liquid (c) Gas • On the basis of Macroscopic or bulk level, matter can be divided into – (a) Mixture – which are further divided into – (i) Homogeneous mixture (ii) Heterogeneous …

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Dalton’s Atomic Theory of Matter , Drawbacks and Importance

Read First – Law of Conservation of Mass Law of Definite Proportions / Constant Composition Mole Concept – Importance and formulas       John Dalton FRS (6 September 1766 – 27 July 1844) John Dalton was an English chemist, physicist, and meteorologist. He is best known for proposing the modern atomic theory and for his research into colour blindness, sometimes referred …

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How to solve Problems based on Law of Definite Proportions / Constant Composition

Read first – What is Matter? What is its Characteristics? States of Matter Law of Conservation of Mass Problems based on Law of Conservation of Mass Law of Definite Proportions / Constant Composition Mole Concept – Importance and formulas Problem 1 : One mole of  V2O5 contains 5 moles of oxygen atoms, as it is clear from …

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Law of Definite Proportions / Constant Composition

Read First – What is Matter? What is its Characteristics? States of Matter Law of Conservation of Mass Problems based on Law of Conservation of Mass The law of definite proportions or constant composition states that – “All pure samples of a particular chemical compound, the constituent elements are always combined in the same proportions …

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Laws of Chemical Combination – Law of Conservation of Mass

Read more – What is matter? What is its Characteristics? States of matter Mole Concept – Importance and formulas There are four laws of chemical combination. They are – 1. The law of conservation of mass 2. The law of constant (definite) proportions 3. The law of multiple proportions 4. The law of reciprocal proportions …

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Change of States of Matter – [B] Effect of change of Pressure

Read First – Can Matter change its States? States of Matter What is Matter? What is its Characteristics? [B] Effect of change of Pressure – Liquified petroleum gas . By increasing pressure, particles of matter can be brought close together. When we apply pressure on a gas enclosed in a cylinder, it  starts compressing and converts …

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A CHEMICAL REACTION IS CHARACTERIZED BY FORMATION OF A PRECIPITATE.

When a chemical reaction occurs, following observations help us to determine whether a chemical reaction has taken place. (1) Formation of a precipitate (2) Change in colour (3) Evolution of a gas (4) Change in state (5) Change in temperature or evolution / absorption of heat (6) Sound, light may be produced. (7) Change in …

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