GENCHEM (WEEK 1).pdf

INTRODUCTION TO MATTER Properties of Matter Chemistry deals with.. Physical and chemical changes are manifestations of physical and chemical ‣ Composition of matter...

INTRODUCTION TO MATTER Properties of Matter Chemistry deals with.. Physical and chemical changes are manifestations of physical and chemical ‣ Composition of matter properties. ‣ Structure of matter A physical property is a property that a substance displays without changing ‣ Properties of matter its composition, whereas a chemical property is a property that a substance ‣ Changes that matter undergoes displays only by changing its composition via a chemical change. ‣ Energy which accompanies the change MATTER - is anything that has mass and occupies space What is chemistry? The branch of science that deals with the identification of the substances of which matter is composed; the investigation of their properties and the ways in which they interact, combine, and change; and the use of these processes to form new substances. Classification of Matter Matter can also be define through its extensive and intensive properties. An extensive property is a property that changes their value when the amount of matter is changed, whereas an intensive property is a property that does not change their value when the amount of matter is changed. Matter undergoes changes... Changes that alter only state or appearance, but not composition, are physical changes. The atoms or molecules that compose a substance do not change their identity during a physical change. Changes that alter the composition of matter are chemical changes. During a chemical change, atoms rearrange, transforming the original substances into different substances. PROPERTIES OF SUBSTANCE Malleablity Malleability describes the property of a metal's ability to be distorted below Conductor compression. It is a physical property of metals by which they can be A conductor, or electrical conductor, is a substance or material that allows hammered, shaped and rolled into a very thin sheet without rupturing. electricity to flow through it. In a conductor, electrical charge carriers, usually electrons or ions, move easily from atom to atom when voltage is Ductility applied. Is the ability of a material to be drawn or plastically deformed without fracture. It is therefore an indication of how 'soft' or malleable the material is. Insulator An insulator is a material that does not conduct electrical current. Insulating Solubility materials include paper, plastic, rubber, glass and air. Vacuum is also an Solubility is defined as the maximum amount of a substance that will insulator, but is not actually a material. Most electrical conductors are dissolve in a given amount of solvent at a specified temperature. Solubility is covered by insulation. a characteristic property of a specific solute–solvent combination, and different substances have greatly differing solubilities. Density It depends on the temperature and pressure when it is measured. These Boiling Point materials are arranged form highest to lowest density measured at 0 Boiling point, temperature at which the pressure exerted by the degrees C and 1 atmospheric pressure. Substances with smaller more surroundings upon a liquid is equaled by the pressure exerted by the vapour massive atoms that are close together have higher density of the liquid; under this condition, addition of heat results in the transformation of the liquid into its vapour without raising the temperature. Acidity Acidity is the characteristic of any substance that is acidic, which can turn Melting Point blue litmus paper red. The acidity of a solution determines its ability to form The melting point of a substance is the temperature at which it changes a reaction with various metals and bases and to produce salts. The most state from solid to liquid. At the melting point the solid and liquid phase common corrosives can be either strong bases or strong acids. Some solids, exist in equilibrium. liquids and gases as well as vapor may have strong acidity that can lead to Polarity corrosion of substances as well as chemical burns. Acidic solutions normally Is a separation of electric charge leading to a molecule or its chemical have pH below 7.0. The lower the pH, the more acidic a solution is, which also means higher hydrogen ion concentration. groups having an electric dipole moment, with a negatively charged end and a positively charged end. polarity, in chemical bonding, the distribution of Flammability electrical charge over the atoms joined by the bond. Flammability is the ease with which a material is ignited, the intensity with Elasticity which it burns and releases heat once ignited, its propensity to spread fire, Ability of a deformed material body to return to its original shape and size and the rate at which it generates smoke and toxic combustion products when the forces causing the deformation are removed. A body with this during gasification and burning. ability is said to behave (or respond) elastically. Reactivity Corrosiveness Reactivity is a measure of how readily a substance undergoes a chemical A property of material that causes gradual destruction by a chemical reaction. The reaction can involve the substance on its own or with other reaction such as strong acids, oxidizers, and bases. atoms or compounds, generally accompanied by a release of energy.  COMMON CHEMICAL SUBSTANCE The ingredients or materials of the consumers' products, such as food, medicine, and other products written in their chemical formula form, confuse the consumers. Most of us consider formulas foreign to us due to the lack of understanding of these chemical formulas. We associate chemical formulas with chemists only. CHEMICAL - refers to a compound or substance FORMULA - Symbolic Expression Chemical Substance It is a form of matter having a constant chemical composition and characteristic properties. Chemical substances are often called 'pure' to set them apart from mixtures. A typical example of a chemical substance is pure water; it has the same properties and ratio of hydrogen to oxygen, whether isolated from a river or made in a laboratory Chemical Formula A symbolic expression of a compound or substance. It is also described as shorthand for expressing the types and the number of atoms in a substance. In the chemical formula, the chemical symbols, and the number of atoms for each element present in the compound can be depicted For example, CO2 is the chemical formula of a substance known as Carbon dioxide. Based on its formula of CO2, the said compound is made up of two types of atoms: carbon and oxygen. The formula has two letters written in the capital: C and O. The capital letter is a chemical symbol representing a particular substance known as an element.  CONSUMER PRODUCTS Toothpaste The first active ingredient in toothpaste that plays a large role in keeping Globally Harmonized System (GHS) your teeth clean is Sodium Fluoride. Not only does Sodium Fluoride prevent Classification and Labeling of Chemicals further tooth decay, it can repair previous minor tooth decay. Sodium GHS has 9 pictograms that represent the physical, health and Fluoride repairs your teeth by replacing the lost calcium and phosphorus. environmental hazards of chemicals. When it reaches your teeth, the enamel absorbs it and the lost minerals are replaced in the process called remineralization keeping the teeth hard. This helps slow down the dissolution of the minerals in the demineralization phase and the strengthening of the teeth protects them from the bacteria in your mouth that produce decaying acids. Alcohol-based and Alcohol – free Hand Sanitizer On hand sanitizers containing alcohol, the labelled alcohol contents are often referred to as ethanol, ethyl alcohol, isopropanol or 2-propanol, whereas hand sanitizers containing no-alcohol usually display Benzalkonium Chloride combined with water and other ingredients that help to moisturize and soften the skin. It’s been advised by both the CDC and the World Health Organization that if hand sanitizer is used, it’s best to go for one with at least 60% alcohol as the alcohol content has been proven to kill over 99.9% of germs. As alcohol-based hand sanitizers can often be harsher on the skin when used frequently, providing non-alcohol-based hand sanitizer may be better particularly if the end user has sensitive skin. Soaps The soap molecule has two different ends, one that is hydrophilic (polar head) that binds with water and the other that is hydrophobic (non-polar hydrocarbon tail) that binds with grease and oil. Since soap molecules have both properties of non-polar and polar molecules soap can act as an emulsifier