Lecture In Chemistry 1 PDF

VIII. INSTRUCTIONAL STRATEGIES  Pre-Lection (Activating Prior Knowledge) “Learning Checkpoints” Instruction:  Given the picture, analyze what word is being described.  Explain how does it represents? Interactive Lecture (Focus Instruction- “I Do”)...

VIII. INSTRUCTIONAL STRATEGIES  Pre-Lection (Activating Prior Knowledge) “Learning Checkpoints” Instruction:  Given the picture, analyze what word is being described.  Explain how does it represents? Interactive Lecture (Focus Instruction- “I Do”) INTRODUCTION TO MATTER AND ITS PROPERSTIES As we look at our surroundings, we see a large variety of things with different shapes, sizes, and textures. Everything in this universe is made up of material that scientists have named “matter”. The air we breathe, the food we eat, stones, clouds, stars, plants and animals, even a small drop of water or a particle of sand – everything is matter. We can also see as we look around that all the things mentioned above occupy space and have mass. In other words, they have both mass and volume. Matter - is anything that has mass and occupies space. Everything that we can touch, see, hear, taste and also smell is matter. It is made up of really tiny particles which cannot be seen through the eye The particles of which the matter is comprised influence its state and properties (physical and chemical).  STATES OF MATTER Matter can be classified as solid, liquid, and gas on the basis of interparticle and the arrangement of particles.  CHEMICAL AND PHYSICAL PROPERTIES Some properties can be readily measured with our senses, e.g. odor and color, instruments are needed to measure other properties, such as electrical resistivity, hardness, melting point, boiling point, density, mass, volume, etc. Chemical Properties - describe the reactivity of a substance toward other substances. Examples include: Ethanol burns in air (reacts with oxygen) Sodium reacts vigorously with water, Corrosion of metal parts (rust), Trinitrotoluene (TNT) is explosive. Physical changes - are changes in matter that do not change the composition of a substance. – Examples include changes of state, temperature, and volume. Chemical changes result in new substances. – Examples include combustion, oxidation, and decomposition. PROPERTIES OF MATTER Intensive Properties: Independent of the amount of the substance that is present. Density, boiling point, color, etc. Extensive Properties: Dependent upon the amount of the substance present. Mass, volume, energy, etc. Pure substances are substances that are made up of only one kind of particle and have a fixed or constant structure. Pure substances are further classified as elements and compounds. Element - is a substance that consists of only one type or kind of atom. An element is a pure substance as it cannot be broken down or transformed into a new substance even by using some physical or chemical means. Elements are mostly metals, non-metals or metalloids. Example: All elements are mostly pure substances. A few of them include gold, copper, oxygen, chlorine, diamond, etc. Compounds - are also pure substances when two or more elements are combined chemically in a fixed ratio. However, these substances can be broken down into separate elements by chemical methods. Example: Water, salt or crystals, baking soda amongst others are also grouped as pure substances. Mixture – is a physical blend of two or more substances. Mixture is an Impure substance are also called mixtures. Mixtures are further divided into homogenous or heterogeneous mixture. Homogeneous mixtures  are mixture that have uniform composition and properties  have a single phase  cannot be separated by physical mean  Homogeneous mixtures are blended so thoroughly, it looks like one substance, Heterogeneous mixture  mixtures have non-uniform composition and properties.  have two or more phases.  can be separated by physical means.  are not thoroughly blended, so you can see and pick out an individual part of the mixture. EXAMPLES OF COMMON CHEMICAL SUBSTANCE AND ITS FORMULA Mixtures - are physical combination of two or more substances. They can be separated by physical process. The method of separating mixture into its components depends primarily on the properties of each of the components. The following are the more common methods of separating a mixture: 1. Distillation is used to separate mixture containing volatile components. Simple Distillation – is used when the liquid components in the solution have widely different boiling points or when a dissolve solid remains in the distilling flask as its solvent distills off. 2. Chromatography – a technique for separating the components of a mixture based on their distribution between a moving fluid and a stationary phase. 3. Decantation is a process that separates components of a mixture based on differences in density. The layer closer to the top of the container—the less dense of the two liquids, or the liquid from which the precipitate or sediment has settled out—is poured off, leaving denser liquid or the solid behind. 4. Evaporation – is used to separate a soluble solid from a liquid. For example, copper sulfate is soluble in water – its crystals dissolve in water to form copper sulfate solution. During evaporation, the water evaporates away leaving solid copper sulfate crystals behind.  5. Filtration – is used to separate mixture that contain both an insoluble solid and liquid. For example, it can have used to separate a mixture of sand and water. Mater and its Properties in Action