9 Chemistry chapter 1 Sir Suhail Lakho.pdf

SUPERIOR SCHOOL & COLLEGE SHAHDADPUR CHAPTER # 01 FUNDAMENTALS OF CHEMISTRY CHAPTER # 01 FUNDAMENTALS OF CHEMISTY C...

SUPERIOR SCHOOL & COLLEGE SHAHDADPUR CHAPTER # 01 FUNDAMENTALS OF CHEMISTRY CHAPTER # 01 FUNDAMENTALS OF CHEMISTY C H E M I S T R Y : Chemistry is the branch of science which deals with the properties, composition and structure of matter. Chemistry also deals with the changes involved in the matter. BASIC DEFINITIONS M A T T E R : Anything that has mass and occupies space (volume) is called matter. STATES OF MATTER There are five states of matter. Energy increases from solid to liquid, liquid to gases and gases to plasma. a) SOLID: Solid is the state of matter that has definite shape and volume. b) LIQUID: Liquid is the state of matter that has definite volume but has not definite shape. c) GAS: Gas is the state of matter that has neither definite shape nor volume. d) PLASMA: Plasma is the fourth state of matter. Plasma is superheated matter containing significant number of electrically charged particles. e) BOSE-EINSTEIN CONDENSATE (BEC): Bose-Einstein condensate is the fifth state of matter. It is super cooled matter having no any molecular motion. ATOM: Atom is the smallest particle of matter that takes part in a chemical reaction. OR Atom is the complex organization which is composed of three subatomic particles. SUBATOMIC PARTICLES / FUNDAMENTAL PARTICLES OF ATOM 1) ELECTRON: Electron is negatively charged particle. It revolves around the nucleus in atom. 2) PROTON: Proton is positively charged particle. It is present in the nucleus of an atom. 3) NEUTRON: Neutron is uncharged particle. It is present in the nucleus of an atom. S U B S T A N C E : A piece of matter in pure form is termed as a substance. Every substance has a fixed composition and specific properties. Example: Tin, sulphur, diamond, water, pure sugar (sucrose), table salt (sodium chloride) etc. E L E M E N T : An element is a substance made up of same type of atoms, having same atomic number and cannot be decomposed into simple substances by ordinary chemical reaction. TYPES OF ELEMENTS a) METALS: Solid material which are typically hard, shiny, malleable, fusible, and ductile, with good electrical and thermal conductivity (e.g. iron, gold, silver, and aluminum, and alloys such as steel). b) NON-METALS: Non-metals are elements that don't have the characteristics of metals including ability to conduct heat or electricity, luster, or flexibility. An example of a nonmetal element is carbon. c) METALOIDS: Elements (e.g. arsenic, antimony, or tin) whose properties are intermediate between those of metals and solid non-metals. They are semiconductors. S Y M B O L : Symbol is an abbreviation to represent the name of elements. A symbol is taken from the name that elements from English, Latin, Greek and German. 1|Page SUHAIL MUHAMMAD LAKHO (CHEMISTRY LECTURER)  SUPERIOR SCHOOL & COLLEGE SHAHDADPUR CHAPTER # 01 FUNDAMENTALS OF CHEMISTRY V A L E N C Y : The combining power of an element with other element is called valency. The valency depends upon the number of electrons in the outermost shell. OR Valency is the number of electrons of an atom of an element can gain, lose or share. FIRST TWENTY (20) ELEMENTS S. No. NAME SYMBOL ATOMIC NUMBER ATOMIC MASS VALENCY 1 Hydrogen H 1 1 a.m.u. 1 2 Helium He 2 4 a.m.u. 0 3 Lithium Li 3 7 a.m.u. 1 4 Beryllium Be 4 9 a.m.u. 2 5 Boron B 5 11 a.m.u. 3 6 Carbon C 6 12 a.m.u. 4 7 Nitrogen N 7 14 a.m.u. 3 8 Oxygen O 8 16 a.m.u. 2 9 Fluorine F 9 19 a.m.u. 1 10 Neon Ne 10 20 a.m.u. 0 11 Sodium Na 11 23 a.m.u. 1 12 Magnesium Mg 12 24 a.m.u. 2 13 Aluminum Al 13 27 a.m.u. 3 14 Silicon Si 14 28 a.m.u. 4 15 Phosphorus P 15 31 a.m.u. 3, 5 16 Sulphur S 16 32 a.m.u. 2 17 Chlorine Cl 17 35.5 a.m.u. 1 18 Argon Ar 18 39.9 a.m.u. 0 19 Potassium K 19 39 a.m.u. 1 20 Calcium Ca 20 40 a.m.u. 2 C O M P O U N D : The compound is a pure substance formed when two or more elements are chemically bonded together in a fixed ratio by mass. Example: NaCl, CuSO4 , KBr are ionic compounds and H2 O, CH4 , H2 SO4 are covalent compounds. ELEMENT COMPOUND Element is pure substance that is composed of same type Compound is formed by a chemical combination of atoms of atoms having same atomic number. of the different elements. Every compound represented by symbol. Every compound represented by chemical formula. Elements cannot be broken down by chemical reactions. Compounds can be easily separated into simpler substances by chemical reactions. Elements can be distinguished by their atomic number. Compounds are distinguished by their fixed ratio of different elements (arranged in a defined manner). Elements are classified as either metals, nonmetals or Compounds are classified according to their bonds which metalloids. can be ionic, molecular or metallic compounds. Some of the examples of elements are Iron, Copper, Gold, A few examples of compounds are NaOH, NaCl, H2O, etc. C6H12O6 etc. M O L E C U L E : A molecule is the smallest particle in a chemical element or compound that has the chemical properties of that element or compound. Molecules are made up of atoms that are held together by chemical bonds. 2|Page SUHAIL MUHAMMAD LAKHO (CHEMISTRY LECTURER)  SUPERIOR SCHOOL & COLLEGE SHAHDADPUR CHAPTER # 01 FUNDAMENTALS OF CHEMISTRY TYPES OF MOLECULE a) MONOATOMIC MOLECULE: Molecules which consist of only one atom are called monoatomic molecules. Examples: Helium (He), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn) etc. b) DIATOMIC MOLECULE: Molecules which consists of two atoms are called diatomic molecules. Examples: Nitrogen (N2 ), oxygen (O2 ), chlorine (Cl2 ), bromine (Br2 ), iodine (I2 ) etc. c) TRIATOMIC MOLECULE: Molecules which consists of three atoms are called triatomic molecules. Examples: Ozone (O3 ), water (H2 O) etc. d) POLYATOMIC MOLECULE: Molecules which consists of many atoms are called polyatomic molecules. Examples: Phosphorus (P4 ), methane (CH4 ), sulphur (S8 ) etc. e) HOMOATOMIC MOLECULE: Molecules which consists of same types of atoms are called homoatomic molecules. Examples: Phosphorus (P4 ), nitrogen (N2 ), ozone (O3 ), sulphur (S8 ) etc. f) HETEROATOMIC MOLECULE: Molecules which consists of different types of atoms are called heteroatomic molecules. Examples: carbon dioxide (CO2 ), water (H2 O), ammonia (NH3 ) etc. ATOM MOLECULE Atom is the smallest particle of an element. Molecule is the smallest particle in a chemical element or compound. Atom has chemical properties of that element. Molecule has chemical properties of that element or compound. Atom is electrically neutral. Molecule is always neutral. Atom can or cannot exist independently. Molecule is stable unit and can exist independently. Atom is the smallest particle. Molecule is formed by the combination of atoms. M I X T U R E : An impure substance that contains two or more pure substances that retain their individual chemical characteristics is called a mixture. OR When two or more elements or compounds physically without any fixed ratio is known as mixture. TYPES OF MIXTURE There are two main types of mixtures. 1) H O M O G E N E O U S M I X T U R E : Homogeneous mixture. In a homogenous mixture all the substances are evenly distributed throughout the mixture (Saltwater, air, blood). 2) H E T E R O G E N E O U S M I X T U R E : Heterogeneous mixture the substances are not evenly distributed (chocolate chip cookies, pizza, rocks). TEST YOURSELF Q1: What elements do the following compounds contains? (a) Washing soda (Na2 CO3. 10H2 O) (b) Sugar (C12 H22 O11 ) (c) Sand (SiO2 ) (d) Caustic soda (NaOH) Q2: Identify mixture, element or compound from the followings? Table salt, ice-cream, blood, silicon, coca cola, tin, zinc, water, sulphur ATMOIC NUMBER & ATOMIC MASS A T O M I C N U M B E R ( Z ) : The number of protons in the nucleus of an atom of any atom is known as its atomic number. It is represented by symbol Z. For example: The atomic number of carbon = 6 M A S S N U M B E R ( A ) : The total number of protons and neutrons present in the nucleus of an atom is known as mass number. It is represented by symbol A. A=Z+n For example: The mass number of carbon = 12 R E L A T I V E A T O M I C M A S S (Ar): The Relative atomic mass of an atom is the average mass of naturally occurring isotopes as compared to the mass of one atom of carbon (C-12). 3|Page SUHAIL MUHAMMAD LAKHO (CHEMISTRY LECTURER)  SUPERIOR SCHOOL & COLLEGE SHAHDADPUR CHAPTER # 01 FUNDAMENTALS OF CHEMISTRY The unit of relative atomic mass is atomic mass unit, with symbol a.m.u. 1 a. m. u. = 1.66 x 10−24 grams C H E M I C A L F O R M U L A : The chemical formula represents the symbol of elements and ratios of elements to one another in a compound. OR Chemical formula is the combination of symbols of atoms and ions that are held together chemically in compound. Example: Chemical formula of water is H2 O which indicates that 2 atoms of hydrogen combines with 1 atom of oxygen. TYPES OF CHEMICAL FORMULA 1) MOLECULAR FORUMLA: The molecular formula is the formula which shows actual number of atoms of each element present in a molecule. Example: Molecular Formula of benzene is C6H6, which have six carbon and six hydrogen, molecular formula is an integral multiple (1, 2, 3, etc.) of the empirical formula. Molecular Formula = (Empirical Formula)n where, n = 1,2,3, etc 2) EMPIRICAL FORMULA: The formula which shows minimum relative numbers (simplest ratio) of each type of atoms in a compound is called empirical formula. Example: (a) Benzene has molecular formula C6H6. Which has simplest ratio f hydrogen and carbon is 1: 1, so the empirical formula becomes CH. (b) Glucose has molecular formula C6H12O6. It shows the ratio as follows: C6 H12 O6 6: 12: 6 1: 2: 1 C H2 O So, the empirical formula of glucose is CH2 O and have simple ratio 1: 2: 1 of atoms in molecule of glucose. COMPOUND MOLECULAR FORMULA EMPIRICAL FORMULA Carbon dioxide.CO2.CO2 Glucose.C6 H12 O6.C H2 O Hydrogen peroxide.H2 O2.HO Benzene.C6 H6.C H Acetic acid.CH3 COOH.C H2 O Sulphuric acid.H2 SO4.H2 SO4 DIFFERENCES BETWEEN MOLECULAR & EMPIRICAL FORMULAE MOLECULAR FORMULA EMPIRICAL FORMULA Molecular formula shows the actual number of each type of Empirical formula only shows minimum relative numbers atoms in a compound. (simplest ratio) of each type of atoms in a compound. Covalent compounds are represented by molecular Ionic compounds are represented by empirical formula. formula. Molecular formula of glucose is C6 H12 O6. Empirical formula of sodium chloride is NaCl. M O L E C U L A R M A S S : The molecular mass is the sum of atomic masses of all the atoms present in a molecule of a substance. For example, molecular mass of CO2 is 44 a.m.u and H2 O is 18 a.m.u. Example: Calculate the molecular mass of HNO3. Solution: Atomic masses of H = 1 a.m.u, N = 14 a.m.u O = 16 a.m.u Molecular mass = 1 (Atomic mass of H)+1 (Atomic mass of N)+3 (Atomic mass of O) Molecular mass = 1 (1) + 1 (14) + 3 (16) Molecular mass = 1 + 14 + 48 = 63 a. m. u. 4|Page SUHAIL MUHAMMAD LAKHO (CHEMISTRY LECTURER)  SUPERIOR SCHOOL & COLLEGE SHAHDADPUR CHAPTER # 01 FUNDAMENTALS OF CHEMISTRY F O R U M L A M A S S : The sum of the atomic masses of all the atoms in the formula unit of a substance is called formula mass. For example, formula mass of sodium chloride is 58.5 a.m.u Example: Calculate the formula mass of Al2(SO4)3. Solution Atomic masses of Al = 27 a.m.u ,S = 32 a.m.u, O = 16 a.m.u Formula unit = Al2 (SO4 )3 Formula mass of Al2 (SO4 )3 = 2 (Atomic mass of Al)+3(Atomic mass of S + 4 (Atomic mass of O)) Formula mass of Al2 (SO4 )3 = 2 (27) + 3 (32 + 4 (16)) Formula mass of Al2 (SO4 )3 = 54 + 3 (32 + 64) Formula mass of Al2 (SO4 )3 = 54 + 3(96) = 54 + 288 Formula mass of Al2 (SO4 )3 = 342 a. m. u. CHEMICAL SPECIES Chemical species is a chemical entity, such as particular atom, ion, or molecule. I O N S : Ion is charged particle which is formed when an atom gains or loses electrons. Example: Na+ , Cl− etc. TYPES OF IONS a) CATION: Positive ion is called cation. Cations are formed when an atom loses electrons form its outer most shells. For example: Na+ and K + are cations. The following equation shows formation of cations. Na − −−→ Na+ + 1e̅ b) ANION: Negative ion is called anion. Anions are formed by the gain or addition of electrons to an atom. For example: Cl− and O−2 are anions. The following examples shows formation of an anion by addition of electrons to an atom. Cl + 1e̅ − −−→ Cl− M O L E C U L A R I O N : When a molecule loses, or gains electrons the resulting species is called a molecular ion. For examples; CH4+ , O− 2 etc. TYPES OF MOLECULAR ION a) CATIONIC MOLECULAR ION: Positive molecular ions are called cationic molecular ions. Cationic molecular ion is formed when a molecule loses electrons. Example: CH4 − −−→ CH4+ + 1e̅ b) ANIONIC MOLECULAR ION: Negative molecular ions are called anionic molecular ions. Anionic molecular ion is formed when a molecule gains electron. Example: O2 + 1e̅ − −−→ O− 2 F R E E R A D I C A L S : Free radicals are atoms and group of atoms having odd number of (unpaired) electrons. It is represented by putting a dot over the symbol of an element. Free radical is very reactive chemical species. For example: H ° , Cl° , H3 C ° etc. TEST YOURSELF: Identify the cations, anions, free radicals, molecular ion and molecule from the followings? O2 , H–, N2 , Cl2 , CO3–2, H2 O, Br–, H2 , H3 C° , Na+ CHEMICAL EQUATION & BALANCING CHEMICAL EQUATION C H E M I C A L E Q U A T I O N : Chemical equation chemical equation is shorthand method of describing the chemical reaction in terms of symbols and formulae of substances. FOR EXAMPLE: When two molecules of hydrogen and one molecule of oxygen react two molecules of water formed instead of writing the full names of reactants and products, chemists show this reaction as follows in form of equation. 5|Page SUHAIL MUHAMMAD LAKHO (CHEMISTRY LECTURER)  SUPERIOR SCHOOL & COLLEGE SHAHDADPUR CHAPTER # 01 FUNDAMENTALS OF CHEMISTRY R E A C T A N T S : The starting substances are known as reactants and always written on the left-hand side of arrow. P R O D U C T S : The substances are formed due to reactions of reactants are known as products and written on the right side of arrow. C O E F F I C I E N T : The number written in front of formula is called coefficient which shows number of molecules of that reactant or product. STEPS FOR BALANCING OF CHEMICLA EQUATION The chemical equation must be balance in order to fulfill law of conservation of mass. Mostly chemical equations can be balanced by inspection method (trial and error method). There are following steps for balancing chemical equation: a) Write the correct formula of all reactants on the left side and products on the right side of an arrow. b) Balance the number of atoms on each side. c) If the number of atoms may appear more or less than other side, balance the equation by inspection method. Multiply the coefficient with formula to make the number of atoms same on the both (reactants and products) sides of equation. d) The covalent molecules of hydrogen, oxygen, nitrogen and chlorine exist as diatomic molecules. e.g H2 , O2 , N2 and Cl2. We must write them as diatomic molecule rather than isolated atoms in chemical equation. e) Finally check the equation to be sure that number and kind of atom are same on the reactant and product side. If yes now equation is balanced. MOLE & AVOGADRO’S NUMBER G R A M A T O M I C M A S S : The atomic mass of an element expressed in gram is called gram atomic mass. It is also called 1 mole. Example: 1-gram atom of oxygen = 16.00g = 1 mole of oxygen atom 1-gram atom of carbon = 12.00g = 1 mole of carbon atom G R A M M O L E C U L A R M A S S : The molecular mass of an element or a compound expressed in gram is called gram molecular mass. It is also called 1 mole. Example: 1-gram molecule of oxygen (O2 ) = 32.00g = 1 mole of oxygen molecule 1-gram molecule of water (H2 O) = 18.00g = 1 mole of water G R A M F O R M U L A M A S S : The formula mass of an ionic compound expressed in grams is called gram formula mass. It is also called 1 mole. Example: 1-gram formula of NaCl = 58.5g = 1 mole of sodium chloride 1-gram formula mass of CaCO3 = 100g = 1 mole of calcium carbonate M O L E : The atomic mass, molecular mass and formula mass of a substance expressed in grams is known as mole. OR A mole is defined as “the amount of substance in grams that containing equal to the Avogadro's number (NA ) 6.02 × 1023 (atoms, molecules or formula units) particles of that substance. For example: Atomic mass of carbon expressed as 12 gm = 1 mole of carbon Molecular mass of H2 O expressed as 18 gm = 1 mole of water M O L A R M A S S : The mass of one mole of substance is called as molar mass. Example: Molar mass of carbon dioxide (CO2 ) = 44 grams Molar mass of H2 SO4 = 98 grams M O L E - M A S S C A L C U L A T I O N : In this calculation we calculate number of moles of a substance with the help of following equation. 𝐆𝐢𝐯𝐞𝐧 𝐦𝐚𝐬𝐬 𝐨𝐟 𝐬𝐮𝐛𝐬𝐭𝐚𝐧𝐜𝐞 𝐍𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐦𝐨𝐥𝐞𝐬 = 𝐌𝐨𝐥𝐚𝐫 𝐦𝐚𝐬𝐬 𝐨𝐟 𝐬𝐮𝐛𝐬𝐭𝐚𝐧𝐜𝐞 6|Page SUHAIL MUHAMMAD LAKHO (CHEMISTRY LECTURER)  SUPERIOR SCHOOL & COLLEGE SHAHDADPUR CHAPTER # 01 FUNDAMENTALS OF CHEMISTRY We can calculate mass of a substance with the given moles of substance with following equation. 𝐌𝐚𝐬𝐬 𝐨𝐟 𝐬𝐮𝐛𝐬𝐭𝐚𝐧𝐜𝐞 = 𝐍𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐦𝐨𝐥𝐞𝐬 × 𝐌𝐨𝐥𝐚𝐫 𝐌𝐚𝐬𝐬 Example: Calculate the number of moles in 40g of Na. Solution: Given mass of Na = 40g Molecular mass of Na = 23 a. m. u Number of moles =? 𝐆𝐢𝐯𝐞𝐧 𝐦𝐚𝐬𝐬 𝐨𝐟 𝐬𝐮𝐛𝐬𝐭𝐚𝐧𝐜𝐞 𝐍𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐦𝐨𝐥𝐞𝐬 𝐨𝐟 𝐍𝐚 = 𝐌𝐨𝐥𝐚𝐫 𝐦𝐚𝐬𝐬 𝐨𝐟 𝐬𝐮𝐛𝐬𝐭𝐚𝐧𝐜𝐞 40 Number of moles of Na = = 1.73 moles 23 Example: What is the mass of 4 moles of CO2? Solution: Number of moles of CO2 = 4 moles Molar mass of CO2 = 44 grams Mass of O2 = ? 𝐌𝐚𝐬𝐬 𝐨𝐟 𝐂𝐎𝟐 = 𝐍𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐦𝐨𝐥𝐞𝐬 𝐨𝐟 𝐂𝐎𝟐 × 𝐌𝐨𝐥𝐚𝐫 𝐦𝐚𝐬𝐬 𝐨𝐟 𝐂𝐎𝟐 Mass of CO2 = 4 × 44 = 176 grams A V O G A D R O ’ S N U M B E R (𝐍𝐀 ): A mole is an amount of a substance in grams that contains constant number of particles 6.02 × 1023 of that substance. This experimentally determined constant number is known as Avogadro’s number. It is represented by NA. For example: 1 mole of O2 molecule = 32 g So, 32 grams of O2 will contain 6.02 × 1023 molecules Similarly, 1 mole of NaCl = 58.5g of NaCl = 6.02 × 1023 Na+ + 6.02 × 1023 Cl− M A S S - P A R T I C L E S C A L C U L A T I O N : In this calculation we calculate number of particles (atom, molecules or formula unit) of a substance in the given grams of substance. 𝐆𝐢𝐯𝐞𝐧 𝐦𝐚𝐬𝐬 × 𝐍𝐀 𝐍𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐩𝐚𝐫𝐭𝐢𝐜𝐥𝐞𝐬 = 𝐌𝐨𝐥𝐚𝐫 𝐦𝐚𝐬𝐬 We can calculate mass of particles as: 𝐆𝐢𝐯𝐞𝐧 𝐩𝐚𝐫𝐭𝐢𝐜𝐥𝐞𝐬 × 𝐌𝐨𝐥𝐚𝐫 𝐦𝐚𝐬𝐬 𝐌𝐚𝐬𝐬 𝐨𝐟 𝐩𝐚𝐫𝐭𝐢𝐜𝐥𝐞𝐬 = 𝐍𝐀 Example: Calculate the number of atoms present in 9.2 grams of calcium (Ca). Solution: Molar mass of calcium (Ca) = 40 g Given mass of calcium (Ca) = 9.2 gram NA = 6.02 × 1023 𝐆𝐢𝐯𝐞𝐧 𝐦𝐚𝐬𝐬 𝐨𝐟 𝐂𝐚 × 𝐍𝐀 𝐍𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐚𝐭𝐨𝐦𝐬 = 𝐌𝐨𝐥𝐚𝐫 𝐌𝐚𝐬𝐬 𝐨𝐟 𝐂𝐚 6.02 × 1023 × 9.2 Number of atoms = = 1.384 × 1023 atoms 40 Example: Calculate the mass in grams of 1 molecule of water. Solution: Mass of 1 molecule of H2O = ? Molar mass of water = 18 g NA =6.02 × 1023 𝐆𝐢𝐯𝐞𝐧 𝐩𝐚𝐫𝐭𝐢𝐜𝐥𝐞𝐬 × 𝐌𝐨𝐥𝐚𝐫 𝐦𝐚𝐬𝐬 𝐌𝐚𝐬𝐬 𝐨𝐟 𝟏 𝐦𝐨𝐥𝐞𝐜𝐮𝐥𝐞 𝐨𝐟 𝐰𝐚𝐭𝐞𝐫 = 𝐍𝐀 7|Page SUHAIL MUHAMMAD LAKHO (CHEMISTRY LECTURER)  SUPERIOR SCHOOL & COLLEGE SHAHDADPUR CHAPTER # 01 FUNDAMENTALS OF CHEMISTRY 1 × 18 Mass of 1 molecule of water = 6.02 × 1023 Mass of 1 molecule of water = 2.99 × 10−23 grams M O L E - P A R T I C L E S C A L C U L A T I O N : In this calculation we calculate number of moles of a substance in the given number of particles (atom, molecules or formula unit). 𝐆𝐢𝐯𝐞𝐧 𝐧𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐩𝐚𝐫𝐭𝐢𝐜𝐥𝐞𝐬 𝐆𝐢𝐯𝐞𝐧 𝐧𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐩𝐚𝐫𝐭𝐢𝐜𝐥𝐞𝐬 𝐍𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐦𝐨𝐥𝐞𝐬 = = 𝐍𝐀 𝟔. 𝟎𝟐 × 𝟏𝟎𝟐𝟑 We can calculate number of particles as: 𝐍𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐩𝐚𝐫𝐭𝐢𝐜𝐥𝐞𝐬 = 𝐍𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐦𝐨𝐥𝐞𝐬 × 𝐍𝐀 Example: Calculate the number of moles and number of molecules present in 10 gm of H2 SO4? Solution: Given mass of H2 SO4 = 10 grams Molar mass of H2 SO4 = 98.0 grams Given mass of H2 SO4 10 Number of moles of H2 SO4 = = = 0.10 mole Molar mass of H2 SO4 98 Number of molecules of H2 SO4 = Number of moles × NA Number of molecules of H2 SO4 = 0.10 × 6.02 × 1023 Number of molecules of H2 SO4 = 6.02 × 1022 molecules M O L E - V O L U M E C A L C U L A T I O N : The mole quantities of gases can be expressed in terms of volume, according to Avogadro, one-gram mole of any gas at STP occupies volume of 22.4 dm3 (where standard temperature is 0 ℃ and standard pressures is 1 atm). Molar volume at STP = 22.4 dm3 = 22,400 cm3 𝐕𝐨𝐥𝐮𝐦𝐞 𝐨𝐟 𝐠𝐚𝐬 = 𝐌𝐨𝐥𝐞𝐬 × 𝐌𝐨𝐥𝐚𝐫 𝐯𝐨𝐥𝐮𝐦𝐞 𝐆𝐢𝐯𝐞𝐧 𝐯𝐨𝐥𝐮𝐦𝐞 𝐌𝐨𝐥𝐞𝐬 = 𝐌𝐨𝐥𝐚𝐫 𝐯𝐨𝐥𝐮𝐦𝐞 Example: Calculate the volume in dm3 of 3 moles of CO2 at STP. Solution: Volume of CO2 = ? Given moles of CO2 = 3 moles Molar volume at STP = 22.4 dm3 𝐕𝐨𝐥𝐮𝐦𝐞 𝐨𝐟 𝐂𝐎𝟐 = 𝐌𝐨𝐥𝐞𝐬 × 𝐌𝐨𝐥𝐚𝐫 𝐕𝐨𝐥𝐮𝐦𝐞 Volume of CO2 = 3 × 22.4 Volume of CO2 = 67.2 dm3 Example: Calculate the moles in 60 dm3 of CH4 at STP. Solution: Moles of CH4 = ? Given volume of CH4 = 60 dm3 Molar volume at STP = 22.4 dm3 𝐆𝐢𝐯𝐞𝐧 𝐯𝐨𝐥𝐮𝐦𝐞 𝐌𝐨𝐥𝐞𝐬 𝐨𝐟 𝐂𝐇𝟒 = 𝐌𝐨𝐥𝐚𝐫 𝐯𝐨𝐥𝐮𝐦𝐞 60 Moles of CH4 = 22.4 Moles of CH4 = 2.6786 moles 8|Page SUHAIL MUHAMMAD LAKHO (CHEMISTRY LECTURER)  SUPERIOR SCHOOL & COLLEGE SHAHDADPUR CHAPTER # 01 FUNDAMENTALS OF CHEMISTRY BRANCHES OF CHEMISTRY 1) P H Y S I C A L C H E M I S T R Y : Physical chemistry is the branch of chemistry which deals with relationship between composition and physical properties of matter with the changes in them. OR Physical chemistry is the branch of chemistry which deals with the laws and theories to understand the structure and changes of matter. 2) O R G A N I C C H E M I S T R Y : Organic chemistry is the branch of chemistry which deals with hydrocarbons and their derivatives. OR Organic chemistry is the study of structure, properties, composition, reactions, and preparation of carbon-containing compounds, which include hydrocarbons except oxides, carbonates, bicarbonates and cyanites. 3) I N O R G A N I C C H E M I S T R Y : Inorganic chemistry is the branch of chemistry which deals with the study of all elements and their compound except hydrocarbons. 4) B I O C H E M I S T R Y : Biochemistry is the branch of chemistry which deals with the compounds of living organisms. plants and animals and their metabolism and synthesis in the living body such as carbohydrates, proteins and fats. OR Biochemistry is the branch of chemistry which deals with physical and chemical changes that occur in living organisms. 5) I N D U S T R I A L C H E M I S T R Y : The branch of chemistry that deals with chemical processes involved in chemical industries for the manufacture of synthetic products like fertilizers, glass, cement, and medicines is called as industrial chemistry. 6) N U C L E A R C H E M I S T R Y : Nuclear chemistry is the branch of chemistry which deals with the radioactivity, nuclear processes and properties. OR The branch of Chemistry that deals with the changes that occur in atomic nuclei is called nuclear chemistry. 7) E N V I R O N M E N T A L C H E M I S T R Y : It is the branch of Chemistry which deals with the study of the interaction of chemical materials and their effect on the environment of animals and plants. 8) A N A L Y T I C A L C H E M I S T R Y : Analytical chemistry is the branch of chemistry which deals with separation and analysis of kind, quality and quantity of various components in given substance. SUHAIL MUHAMMAD LAKHO CHEMISTRY LECTURER 9|Page SUHAIL MUHAMMAD LAKHO (CHEMISTRY LECTURER)