GENERAL CHEMISTRY OF THE YEAR 2024 WITH BEST SOLUTIONS (VERIFIED ANSWERS), Exams of Chemistry

Download GENERAL CHEMISTRY OF THE YEAR 2024 WITH BEST SOLUTIONS (VERIFIED ANSWERS) and more Exams Chemistry in PDF only on Docsity! GENERAL CHEMISTRY OF THE YEAR 2024 WITH BEST SOLUTIONS (VERIFIED ANSWERS)  Hypothesis - ✓✓✓An educated guess based on observations, previous knowledge and intuition  Experimentation - ✓✓✓Observations taken under conditions that we can control so we can ask specific questions  Data - ✓✓✓Observations obtained from an experiment  Theory - ✓✓✓A well tested conclusion that can be confirmed through further information  Law - ✓✓✓A very consistent behavior that has universal validity  What is Matter? - ✓✓✓Matter is anything that has mass and occupies space. We can describe matter in terms of physical properties, those characteristics that can be determined without changing the chemical composition of matter (shape, color, texture, shine, odor, taste.) and mass, volume, density, temperature.  How do we classify Matter? - ✓✓✓We classify matter by its physical state:  -Solid: fixed shapes and volumes  -Liquid: variable shapes and fixed volumes  -Gas: variable shapes and volumes  Pure Substance - ✓✓✓Pure substances have the same chemical composition throughout, and from sample to sample. It can also be classified as either elements or compounds (Cannot be separated by purely physical means.)  There are two kinds of pure substance: elements and compounds  Mixtures - ✓✓✓A combination of two or more elements or compounds. They differ from pure compounds in that their components can be separated by physical processes. (i.e: pencil lead, salt water, Air)  Elements - ✓✓✓A substance that cannot be broken down into simpler substances even by a chemical reaction. Separated further into metals and nonmetals.  Compounds - ✓✓✓A substance composed of two or more different elements combined in definite proportions.  Homogeneous Mixtures - ✓✓✓Consists of two or more substances but has the same composition throughout and often called a solution (i.e. salt water)  Heterogeneous Mixtures - ✓✓✓Consists of two or more substances but does not have the same composition throughout (i.e. salt and pepper.)  Physical properties of Matter - ✓✓✓Solid (s): fixed shape, its own volume, no volume change under pressure, and particles are fixed in place in regular array  Liquid (l): shape of container (may or may not fill), its own volume, slight volume change under pressure, and particles are randomly arranged and free to move about until they bump into one another  Gas (g): shape of container (fills it), volume of container, large volume change under pressure, and particles are widely separated and move independently of one another  Aqueous (aq): mixed with molecules of water  Physical change of Matter - ✓✓✓Converting matter between solid, liquid, and gas. The chemical composition does not change (crushed cube of sugar, boiling water to steam, melting iron rod)  -Change of state (water from solid to gas)  -Expected change of color (blue mixed with yellow to make green)  Chemical properties of Matter - ✓✓✓Properties that, in order to be observed, require composition of matter be changed. Descriptions of the ability of a substance to undergo a chemical change (hydrogen burns easily with oxygen, Helium is unreactive, Iron rusts, Silver tarnishes.)  Chemical change of matter - ✓✓✓Alters the makeup of the substance (potassium reacting with water, burning of fuel, rusting of iron.)  -Process in which one or more substances are converted into one or more new substances (bubbling, permanent color change)  Physical State Transitions - ✓✓✓Gas to liquid: condensation  Liquid to gas: Vaporization  Liquid to solid: Freezing  Solid to liquid: Melting  Solid to gas: Sublimation  Gas to Solid: Deposition