Metals and Non-Metals Notes PDF
Document Details
Uploaded by Deleted User
Gaurav Suthar
Tags
Summary
These handwritten notes cover the properties and reactions of metals and non-metals. The document details examples of different reactions with oxygen, water and acids. The key characteristics of each material are described.
Full Transcript
Metals & Non-Metals Handwritten Notes Gaurav Suthar METALS Those elements which form positive ions by losing electrons are called Metals. Physical Properties of Metals - 1. Good Conductor of Heat and Electricity. 2. High melting and Boiling Point 3. So...
Metals & Non-Metals Handwritten Notes Gaurav Suthar METALS Those elements which form positive ions by losing electrons are called Metals. Physical Properties of Metals - 1. Good Conductor of Heat and Electricity. 2. High melting and Boiling Point 3. Solid at room temperature except mercury (liquid) 4. Are Sonorous (means they produce a sound on striking) 5. Are Malleable, i.e., they can be hammered into thin sheets. 6. Are Ductile (means they can be used to make wires) Gold is the most ductile metal means wires of gold can be made easily because gold is very soft for bending. But we can’t use Wires of Gold in our Home (क्यं ू क Gold इतना महँगा है क परू ा घर ह बक जाएगा ) Copper Wire Gold Wire Chemical properties of Metals - 1. Reaction of Metals with Oxygen - Metal + Oxygen → Metal Oxide Examples - 2Mg + O2 → 2MgO 2Cu + O2 → 2CuO Different metals react in different ways with O2 i) Metals like Potassium and Sodium react so strongly with Oxygen that they catch fire if kept in open. So they are kept in Kerosene oil to avoid accidental fires. Sodium stored in Kerosene Magnesium covered with Oxide layer ii) At room temperature, surfaces of metals such as Magnesium, Aluminium, Zinc etc. are covered with a thin layer of oxide, to prevent further oxidation. iii) Silver and Gold do not react with oxygen even at high temperatures. Amphoteric Oxides - Metals oxides which react with both acids as well as bases to produce salts and water are called Amphoteric Oxides. Examples - Al2O3 + 6HCl → 2AlCl3 + H2O Al2O3 + 2NaOH → 2NaAlO2 + H2O 2. Reaction of Metals with Water - Metal + Water → Metal Oxide + Hydrogen Metal Oxide + Water → Metal Hydroxide i) For Sodium (Na) and Potassium (K) - Reaction is violent even with cold water and so exothermic that hydrogen immediately catches fire. Examples - 2Na + 2H2O → 2NaOH + H2 + Heat 2K + 2H2O → 2KOH + H2 + Heat ii) For Calcium (Ca) - Reaction is less violent for hydrogen to catch fire. Examples - Ca + 2H2O → Ca(OH)2 + H2 iii) For Aluminium (Al) and Iron (Fe) - These do not form hydroxide as their oxides are not soluble. They do not react with hot water but with steam. Examples - 2Al + 3H2O → Al2O3 + 3H2 3Fe + 4H2O → Fe3O4 + 4H2 3. Reaction of Metals with Acids - Metal + Dilute Acid → Salt + Hydrogen Examples - Fe + 2HCl → FeCl2 + H2 Mg + 2HCl → MgCl2 + H2 Zn + 2HCl → ZnCl2 + H2 Some metals like Silver, Gold and copper do not react with acid. 4. Reaction of Metals with Solutions of other Metal Salts - Metal A + Salt Solution B → Salt Solution A + Metal B Only more reactive metal can displace a less reactive metal from compound. Examples - Fe + CuSO4 → FeSO4 + Cu Cu + FeSO4 → No Reaction (Because Cu is less reactive than Fe) No Reaction Reactivity Series Reactivity Series is a list of metals arranged in order of their decreasing activities K Most Reactive Metal Na Ca Mg More reactive than Hydrogen Al Zn Fe Pb Hydrogen H Cu Hg Less reactive than Hydrogen Ag Au Least Reactive Metal NON - METALS Those elements which form negative ions by gaining electrons are called Non-Metals. Physical Properties of Non - Metals - 1. Are solids or gases except Bromine (liquid) 2. Low melting and Boiling Point 3. Bad conductor of Heat and Electricity (except Graphite) 4. Are Non - Sonorous (don’t produce a sound on striking) 5. Are Non – Malleable (brittle), means they will break when hammered or stretched 6. Are Non – Ductile. Chemical properties of Non - Metals - 1. Reaction of Non-Metal with Water - Non-Metal + Water → No Reaction 2. Reaction of Non-Metals with Acids - Non-Metal + Acid → No Reaction 3. Reaction of Non-Metals with Oxygen - Non-Metal + Oxygen → Non-Metal Oxide Examples - C + O2 → CO2 4. Reaction of Non-Metals with Metal - Non-Metal + Metal → Salt/ Metal Oxide Examples - Na + Cl → NaCl Ionic - Compounds The compounds formed by the transfer of electrons from a metal to a non-metal are called Ionic Compounds. Properties of Ionic Compounds - 1. They are Solid and Hard 2. High Melting and Boiling Point 3. Soluble in Water and insoluble in Petrol, Kerosene 4. Good Conductors of electricity in Aqueous Solution and Molten state but do not conduct in Solid state. Examples – Formation of NaCl Na → Na+ + e- Cl + e- → Cl- (2,8,1) (2,8) (2,8,7) (2,8,8) stable octet Na + Cl → Na Cl (2,8) (2,8,8) stable octet stable octet Common Salt - (Tata Salt - दे श का नमक ) Occurrence of Metals Minerals - The elements or compounds which occur naturally in the earth’s crust are called minerals. Ores - Minerals that contain very high percentage of particular metal and the metal can be profitably extracted from it, such minerals are called ores. K Na Not found in free state Very Reactive Metals Ca Extraction by electrolysis Mg Al Zn Fe Occur as sulphides, oxides, Moderately Reactive carbonates Pb Cu Reduction by using carbon Hg Ag Least Reactive Occur in free state Au Extraction of Metals from Ores Step 1) Enrichment of Ores. Step 2) Extraction of Metals. Step 3) Refining of Metals. Ore Concentration of Ore Metals with High Metals of Medium Metals with Low reactivity reactivity reactivity Electrolysis of Sulphide Ores Molten Ore Carbonate Ores Sulphide Ores ZnCO3 ZnS Pure Metal Calcination Roasting Roasting Oxides of Metal Reduction to Metal Metal Purification of Metal Refining Carbonate Ores Sulphide Ores Steps involved in Extraction of Metals from Ores Some Important Terms a) Gangue - Ores are usually contaminated with large amount of impurities such as soil, sand etc. This is called gangue. b) Roasting - The sulphide ores are converted into oxides by heating strongly in the presence of excess air. 2ZnS + 3O2 → 2ZnO + 2SO2 c) Calcination - The carbonate ores are changed into oxides by heating strongly in limited air. ZnCO3 → ZnO + CO2 d) Reduction - Metal oxides are reduced to corresponding metals by using reducing agent like carbon. ZnO + C → Zn + CO Refining of Metals The most widely used method for refining impure metal is electrolytic refining. e- e- Cathode Anode Anode - Impure copper Cathode - Strip of pure copper Electrolyte - Solution of acidified copper sulphate a) On passing the current through electrolyte, the impure metal from anode dissolves into the electrolyte. b) An equivalent amount of pure metal from the electrolyte is deposited at cathode. c) The insoluble impurities settle down at the bottom of the anode and is called anode mud. Corrosion The surface of some metals such as iron is corroded when they are exposed to moist air for a long period of time. i) Silver becomes black when exposed to air as it reacts with air to form a coating of silver sulphide. ii) Copper reacts with moist carbon dioxide in the air and gains a green coat of copper carbonate. iii) Iron when exposed to moist air acquires a coating of a brown color called Rust. Prevention of Corossion The rusting of iron can be prevented by painting, oiling, greasing, galvanizing, chrome plating, or make alloys. Galvanization - It is a method of protecting steel and iron from rusting by coating them with a thin layer of zinc. Alloy - An alloy is a homogenous mixture of two or more metals or a metal and a non-metal. Iron - Mixed with small amount of carbon becomes hard and strong. Steel - Iron + Nickel and Chromium Brass - Copper + Zinc Bronze - Copper + Tin Search “Gaurav Suthar” on YouTube for more Notes. Love You 3000 ♡ Follow me on Instagram @iamgauravsuthar Gaurav990823@okaxis I have created all Subjects and all Chapters Notes