general-chemistry-prelims-reviewer.pdf

lOMoARcPSD|39517643 General Chemistry Prelims Reviewer General Chemistry (Holy Angel University) Scan to open on Studocu Studocu is not sponsored or endorsed by any college or university Downloaded by Erickha Galvez (galv...

lOMoARcPSD|39517643 General Chemistry Prelims Reviewer General Chemistry (Holy Angel University) Scan to open on Studocu Studocu is not sponsored or endorsed by any college or university Downloaded by Erickha Galvez ([email protected])  lOMoARcPSD|39517643 SHS 11 | 2ND SEM PRELIMS REVIEWER GEN CHEM CHEMICAL PROPERTIES - Properties a substance shows as it CHEMISTRY interacts with, or transforms into other - study of matter, its properties, the substances changes that matter undergoes, and the - Uses chemical change to describe the energy associated with these changes matter - Describes how a substance interacts with FOUR ASPECTS IN STUDYING MATTER other chemicals causing a change in 1. COMPOSITION - the types and amounts composition of simpler substances that make up a 1. CORROSION AND DECOMPOSITION sample of matter (breaking down chemicals) 2. PROPERTIES - the characteristics that 2. COMBUSTION (ability to burn) give each substance a unique identity 3. pH (acidic or basic) 3. CHANGES - chemical reactions involved 4. REACTIVITY (with water and acids) in matter CHANGES OF MATTER 4. ENERGY - describe how much potential  PHYSICAL CHANGE a physical system has to change - Takes place without a change in MATTER composition - Anything that occupies space and has Examples: changes of state, like freezing, mass melting, or evaporation of a substance - Can be distinguished through its:  CHEMICAL CHANGE ATOMIC COMPOSITION - Always accompanied by a change in PROPERTIES (Chemical and Physical) composition - Most color changes PROPERTIES OF MATTER Examples: burning of paper and the fizzing of a mixture of vinegar and baking PHYSICAL PROPERTIES soda - Properties a substance shows by itself without interacting with another STATES OF MATTER substance or without causing a change in the composition of the substance  SOLID: has a fixed volume, and shape that - refers to describe the quality of matter it does not conform to the container; may be possesses hard or soft, rigid or flexible - can be INTENSIVE or EXTENSIVE  LIQUID: has a varying shape that conforms EXTENSIVE: depends on amount (Ex. Mass, to the shape of the container but fills the Volume) container only to the extent of the liquid's INTENSIVE: depends on type of matter (Ex. volume. Liquid forms a surface Hardness)  GAS: conforms to the container shape also,  STATE (solid, liquid, gas) but it fills the entire container; it does not  COLOUR (different for some materials; it forms a surface varies)  Depending on the temperature and  LUSTRE (metallic shine) pressure of surroundings, many substances  CONDUCTIVITY (ability to transmit can exist in each three physical states and electricity) undergo changes in the state as well. As  MALLEABILITY (ductile; bendable) the temperature increases, solid water melts to liquid water, which boils to gaseous Downloaded by Erickha Galvez ([email protected])  lOMoARcPSD|39517643 water. Similarly, with decreasing - Like water, if electric current is applied it temperature, water vapor condenses to split into Hydrogen gas and oxygen gas liquid water, and with further cooling, the liquid freezes to ice  Elements are metals because they high boiling and melting point, hard, ductile, CLASSIFICATION OF MATTER malleable, high density such as Sodium  Elements are non-metals because they have low boiling and melting point, brittle, dull, and low density such as Chlorine  Elements are metalloids because they possess same properties of metals and non- metals COMMON COMPOUNDS FOUND IN OUR HOUSE:  Sodium Chloride (NaCl) – table salt used  Matter can be classified into two categories: in food pure substance and mixture  Sodium bicarbonate (NaHCO3) – baking soda used in food, cleaning products, PURE SUBSTANCES and antacids - Can be further broken down into elements  Sodium hydroxide (NaOH) – lye used in and compounds soaps and drain cleaner - composed of one type of atom or  Potassium nitrate (KNO3) – saltpeter used molecule in fertilizer, gunpowder, and food ELEMENT preservatives - The simplest type of matter with unique FORMULAS OF COMMON CHEMICAL SUBSTANCE physical and chemical properties  Chemical formula are used to shorten the - Consists of only one type of atom name of the compounds - Cannot be broken down into any simpler  It consists of symbols and ratios of the substances by physical or chemical atoms of the elements in a compound means - There are 94 existing element in nature and 24 are artificially made by man MOLECULE - A structure that consists of two or more atoms that are chemically bound together and thus behaves as an independent unit - Ex. Oxygen (O2) [Diatomic molecules] COMPOUND - A substance composed of two or more Compounds can be an acid, base or a salt. elements which are chemically These are examples of acids, bases and salts found inside the laboratory. combined - Can easily be broken by chemical means Downloaded by Erickha Galvez ([email protected])  lOMoARcPSD|39517643  Acids – HCl, H2SO4, HNO3, HC2H3O2 - composition of homogeneous mixtures is  Bases – NaOH, KOH, Ca(OH)2, Mg(OH)2 , constant Al(OH)3 - Has one uniform appearance and one  Salts – NaCl, MgSO4, NaNO3, AlCl3, SiO2 visible phase ACIDS - EX. Brass (made up of zinc and copper) - substances that produce hydrogen ions H+ in water - can conduct electricity and taste sour and it has a pH < 7 BASES - substances that produce hydroxide ions (OH-) in water - taste bitter, slippery feeling, corrosive and can conduct electricity and has a pH > 7 SALTS - product of neutralization process. HETEROGENEOUS MIXTURE - mixture of two or more chemical substances (elements or compounds), where the different components can be visually distinguished and easily separated by physical means - Has a non-uniform appearance and there are two or more visible phases MIXTURE METHODS OF MIXTURE SEPARATION - A group of two or more elements and/or compounds that are physically 1. MECHANICAL SEPARATION (often by intermingled hand) - material system made up of two or more - makes use of tools to separate the different substances, which are mixed but components of mixture such as forceps, not combined chemically strainer, and sieves - refers to the physical combination of two - Takes advantage of physical properties or more substances in which the identities such as color and shape of the individual substances are retained - EX. Recycling plastic, Paper, Metal - take the form of alloys, solutions, suspensions, and colloids 2. MAGNETIC SEPARATION - Takes advantage of the physical property HOMOGENEOUS MIXTURE of magnetism - mixture of two or more chemical - EX. Separating metals in a Scrap Yard substances (elements or compounds), using a magnet where the different components cannot be visually distinguished Downloaded by Erickha Galvez ([email protected])  lOMoARcPSD|39517643 3. FILTRATION - process of separating the insoluble solid from the liquid substance by allowing the liquid to pass through a porous material - porous material used is called filter paper - product after filtration are called residue (a solid left in the the filter paper and filtrate is a liquid found in the beaker - Takes advantage of the physical property of the state of matter 6. DISTILLATION - A screen lets the liquid particles through, - a process that involves the evaporation but traps the solid particles and condensation of liquid solvent from a - Ex. Filtrating brewed coffee grounds with mixture or solution filter paper - uses the difference of boiling point of the - Difference in phase/state of matter components of a mixture and/or solubility - When the mixture is heated, the liquid solvent (lower boiling point) will boil first, 4. DECANTATION/FLOATATION evaporates and condenses into a pure - a method used in which some solid of a liquid suspension mixture are allowed to settle - The product after distillation is called and the less dense material is poured off distillate (Decantation) - Separation of a mixture of liquids based - Takes advantage of differences in density on the physical property of boiling point - EX. panning of gold EX: distillation of alcohol or oil - NEEDED COMPONENTS: 5. EXTRACTION DISTILLING FLASK - Removal of one substance from a mixture HEAT SOURCE: to let the solvent boil and because of its greater solubility in a given evaporate solvent THERMOMETER: to monitor the -