GenChemReviewer.pdf

GENERAL CHEMISTRY REVIEWER substances. Its composition varies. Its boiling or Matter melting point is given in a range, not specifically. It can - Anything that has mass and occupies volume....

GENERAL CHEMISTRY REVIEWER substances. Its composition varies. Its boiling or Matter melting point is given in a range, not specifically. It can - Anything that has mass and occupies volume. also be subdivided into 2: The three particles composing matter are: a. Homogeneous - has only one phase. (You only see 1. Atoms - It is the smallest particle that can enter a ONE physically distinct trait) Ex: Coffee, Wine, Vinegar chemical change. b. Heterogeneous - has 2 or more distinct phases. (You 2. Molecules - It is composed of two or more atoms that can see TWO or MORE physically distinct trait) Ex: Oil are chemically combined. It can consist of only one kind in water, Cereal in milk, Salad, sand and water of atom. Ability to mix or dissolve in water 3. Ions - Charged particles; result from unequal number 1. Soluble/insoluble - Solid is being dissolved. of protons and electrons in an atom. 2. Miscible/immiscible - Liquid is being mixed. PHASE vs STATE Separation Methods Phase - The physically distinct and mechanically - It refers to the methods of separating the components separable parts of a system. of the mixture. State - Condition of a system defined by a set of - Since mixtures are physical combinations of variables. substances, these substances can also be separated System - Refers to the focus of an observation. through physical means. Methods PROPERTIES OF SOLID, LIQUID AND GAS 1. Filtration - Used to separate a solid from a liquid. A Property Solid Liquid Gas mixture with liquid and solid is poured through a filter paper and the solid is left on the filter paper while the Shape Definite Indefinite Indefinite liquid goes into a receiver (beaker) through the funnel underneath the filter paper. The separated solid is called Volume Definite Definite Indefinite residue while the separated liquid is called filtrate. (In simple terms, think of it as if you are straining water Density Large Average Small from your noodles but you want to retain the water.) 2. Evaporation - Used to separate a liquid from a solid Compressibility Almost zero Almost zero Large without the intention of getting the liquid back. A Particle arrangement Compact Slightly far Far apart liquid-solid solution is heated and the liquid is made to apart evaporate and turn into gas. (Sabi ni JONA) 3. Distillation - Used to separate two liquids from each Freedom of motion Small Average Large other. A mixture with two different boiling points is heated, and when one of the liquid has evaporated, it will Properties of Matter turn into gas and pass through an area with a cooler According to change involved during measurement of temperature (Condenser), thus turning it back into a the property: liquid (distillate). The substance left in the flask is 1. Physical - NO change or only physical change called residue. happens to a substance when it is observed. 2. Chemical - Substance undergoes chemical change kaya niyo na po yan.🙂 4. Chromatography - Hindi ko po alam iexplain ito so 5. Decantation - Used to separate a less dense solid or when the property is observed or measured. According to dependence on the amount of matter: liquid from a denser solid or liquid. 1. Intensive - does NOT change with different amounts 6. Scooping of substance. Ex: Density, Temperature, Color, Boiling 7. Magnetic separation - A magnet is used to separate and Melting point. magnetic materials from non-magnetic materials. 2. Extensive - Changes with different amounts of 8. Use of separatory funnel - Used in liquid-liquid substance. Ex: Mass, Volume, Weight, Length. separation. Classes of Matter The ATOM 1. Pure Substance - Substances that are made of a 3 Laws of Chemical Change: single element or compound. It has a definite 1. Law of Conservation of Mass: There is no loss and composition. It has a sharp melting and boiling point. there is no gain. The total mass of the product is equal to Pure substances can be subdivided into two: the total mass of the reactant. a. Element - Composed of only one kind of atoms. 2. Law of Definite Proportion: A compound always b. Compound - composed of 2 or more kinds of atoms. contains its elements in a fixed ratio by mass. 2. Mixture - Physical combination of two or more 3. Law of Multiple Proportions: If two elements can Mga kupal combine to form more than one compound, the masses 2. Chemical Formula - stands for compounds. of one element that will combine with a fixed mass of 3. Chemical Equation - stands for reactions. the other element are in a ratio of small whole numbers. Chemical Formula Law vs Theory Naming compounds Law - Derived from experimental results. 1. Binary compounds - composed of 2 kinds of atoms Theory - Formulated to provide an explanation to the A. Ionic compounds - composed of metal and laws. It can be discarded when it is proven wrong. non-metal atoms that transfer electrons. Naming: add the -ide ending to the 2nd element and just History of the atom name the first element as is. However, for metals with Democritus (Atomism) - theorized the atom and said more than one oxidation number, get the oxidation that the atom is the smallest particle. Also said that the number of the metal, then write it in roman numerals atom is uncut and invisible. between the two elements. John Dalton (Solid Sphere) - Elements are made up of Metals with more than 1 oxidation number: very small particles known as atoms. According to him, 1. Gold (Au) an atom is an empty space. 2. Iron (Fe) I. Elements are made up of very small particles known 3. Mercury (Hg) as atoms. 4. Lead (Pb) II. All the atoms of an element are identical in mass and 5. Tin (Sn) size and are different from the atoms of another element. 6. Copper (Cu) III. Compounds are composed of atoms of more than B. Covalent compounds - composed of 2 nonmetals and one element, combined in definite ratios with whole uses prefixes. number values. Naming: Look at the subscript of the element to IV. During a chemical reaction, atoms combine, determine the prefix to use. separate, or rearrange. No atoms are created, and no Nonmetals to remember: atoms disappear. 1. Hydrogen (H) Joseph John Thomson (Plum Pudding) - The atom is a 2. Carbon (C) sphere, but the positive and negative charges are 3. Oxygen (O) embedded within it. 4. Nitrogen (N) Ernest Rutherford (Nuclear) - Discovered that the 5. Chlorine (Cl) atom has a dense center, which he said is a positively 6. Fluorine (F) charged core called nucleus, around which electrons 7. Bromine (Br) circulate at some distance. 8. Sulfur (S) Neils Bohr (Planetary) - Theorized that the atom is like 9. Iodine (I) a plantery model where the electrons were situated in an 10. Phosphorus (P) orbit with the nucleus at its center. 2. Tertiary compounds - Contains more than 2 Erwin Schrodinger (Quantum) - The locations of the elements. These are compounds with radicals (group of electrons could only be described as being part of a atoms that carry a charge and act as a single unit) “cloud” around the nucleus. Naming: Subatomic particles i) -1 oxygen atom, change ending from -ate to -ite. Proton - Positively charged subatomic particles. Forms ii) - 2 oxygen atoms, change ending from -ate to hypo- the Nucleus along with the Neutron -ite. Neutron - No charge or neutral subatomic particle. iii) + 1 oxygen atom, add the prefix “per-” in addition to Electron - Negatively charged subatomic particles the -ate ending. Important to remember: Atomic number - giives the number of protons in an ONLY sulfate and phosphate have 4 atom. Number of protons = Number of electrons in a OXYGEN atoms normally. neutral atom. 3. Acids Mass number - The sum of the nucleons of an atom. A. Binary acids - contains hydrogen and nonmetal. Neutron + Proton = Mass number Naming: Just use the prefix hydro and add “acid” Isotopes - Atoms of the same element having the same after the element. atomic number but different mass number. B. Ternary acids / Oxy acids - contains hydrogen and a radical. Ionic but metals are replaced with hydrogen. Chemical Language Naming: use the same rules as naming radicals, but 1. Chemical symbols - stands for elements. change -ate to -ic and -ite to -ous, then add acid after the Mga kupal name. Remember: 1. If the decimal is.0 or.9 in the last part, you can round up or down. 2. If the decimal is.5 in the last step, you can multiply Writing Chemical Formula by an integer that will result in a whole number. (.5 X 2) 1. Ionic compound - use the family group to get their Molecular Formula oxidation numbers then criss cross to get their subscripts. - Tells the actual number of atoms of each element in a 2. Covalent compound - just look at the prefixes used, compound. then add the subscript. Steps: 3. Tertiary compound - follow the same rules as ionic 1. Get the formula mass based from the empirical compounds. Use the family group to get their oxidation formula. (Molar mass of the compound in its empirical numbers then crisscross to get their subscripts. formula) 4. Binary acid - Just remember the rules for naming 2. Divide the mass of the molecular formula (Given in radicals. It will only contain 2 elements if it's BINARY. the problem) by the formula mass. 5. Ternary acid - Just remember the -ic and -ous ending N= 𝑀𝑎𝑠𝑠 𝑜𝑓 𝑡ℎ𝑒 𝑚𝑜𝑙𝑒𝑐𝑢𝑙𝑎𝑟 𝑓𝑜𝑟𝑚𝑢𝑙𝑎 𝐹𝑜𝑟𝑚𝑢𝑙𝑎 𝑚𝑎𝑠𝑠 of radicals. It will contain more than 2 elements, a radical and a hydrogen element. 3. (𝐸𝐹)𝑁, where EF is the empirical formula and N is the subscript, then multiply the subscript to the subscript of What you can derive from chemical formula: EF. A. molecular formula B. percentage composition Chemical Equation C. number of moles - Stands for chemical reaction. D. atomic ratio of elements - Has 2 parts, the reactant and the product. E. what elements are present Reactants - The substances that enter a chemical F. mass ratio of elements change/reaction. Product - The substance formed after a chemical change Percentage composition has taken place. - Find the molar mass of the entire compound, then —-> - Separates the reactant and product divide the parts of its molar mass by the whole molar + - Tells us that there is combination and read as “and” mass, then multiply by 100%. S - solid G - gas Molar mass = the sum of the mass of each element x L - liquid their subscript Triangle - heat applied Ex: H2O [o] - oxidizing agent H = 1 x 2 = 2.016 ←– part Arrow left and right - Reversible reaction O = 16 x 1 = 15.99 ←— part Up arrow - evolution of gas 2.016 + 15.99 = 18.015 g/mol ←— molar mass of Down arrow - precipitate (solid) water 𝑃𝐴𝑅𝑇 Percentage = 𝑤ℎ𝑜𝑙𝑒 𝑥 100% How to know if it has undergone chemical reaction: 2.016 1. Change in color %H = 18.015 x 100% = 11.91% 2. Change in intrinsic properties (color, taste, odor) 15.99 3. Production of light %O = x 100% = 88.89% 18.015 4. Change in temperature (Round off if needed) 5. Evolution of gas (bubbles) Empirical formula Types of chemical reaction - The smallest whole number ratio of each element in the 1. Combination/Synthesis - A + B —> AB, 2 reactants, compound. The simplest form of molecular formula. 1 product Steps: 2. Decomposition - C —-> A + B, 1 reactant, 2 A. If given in %, change into grams (assume 100 grams substances in product of sample because it is easier) 3. Combustion - Reaction between fuel and oxygen. B. Convert grams to moles by using their atomic mass Fuel is usually a hydrocarbon. It produces carbon 𝐺𝑖𝑣𝑒𝑛 𝑚𝑎𝑠𝑠 Mole = 𝑎𝑡𝑜𝑚𝑖𝑐 𝑚𝑎𝑠𝑠 dioxide, water, and heat C. Divide the moles of each element by the smallest HC + O2 —-> CO2 + H2O mole. (This will give you the subscripts) 4. Single Displacement - A + BC —-> AB + C, reactant Mga kupal should have an element and 1 compound. excess (This is the amount that was left unreacted). *If element is metal, replace the positive ion in compound. *If element is nonmetal, replace the negative ion in compound. 5. Double Displacement - AB + CD —-> AD + CB Chemical Equation - Balancing is done here. - Obeys law of conservation of mass. Tip ni maam for balancing: If there is an odd number, make it an even number first. Coefficient - It is added to balance the equation. It also tells us the number of moles. We can get the Mole Ratio from it. Stoichiometry - Study of the amounts of reactants consumed and products formed in chemical reactions. - Deals with mole ratio and molar mass. Steps: 1. Balance the chemical equation. 2. Determine the molar mass of the given and unknown, and the Mole Ratio of the Given and the Unknown. 3. Identify which among the three choices should be used to get to the unit that we desire. Choices: A. Molar mass of given B. Mole ratio of given and unknown C. Molar mass of unknown Standard Temperature and Pressure - If a gas is under STP, its volume will be 22.4 L / 1 mol For solving: It follows the same steps as Stoichiometry with the addition of Molar volume, which is 22.4 L / 1 mol. Excess and limiting reagents Limiting reagent - The first to be used up in a chemical reaction. It is used up completely in a reaction. Excess reagent - Present in quantities greater than what is needed by the reaction. These are not completely consumed. To identify limiting and excess reagents: 1. Follow the steps in stoichiometry. 2. Identify which reactant will produce a greater number of moles of the product. 3. The one that produces a greater number of moles will be the excess reagent while the one that produces a small number of moles will be the limiting reagent. 4. If asked how much is the excess, convert them all into grams, then subtract the mass of the product to the mass of the limiting reagent (This is the amount of the excess that reacted with the limiting reagent). Afterwards, subtract the difference from earlier to the mass of the Mga kupal