Chemistry PDF
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This document provides an overview of chemistry topics, including properties of matter, extensive and intensive properties, chemical properties, chemical formulas, and separation techniques.
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Properties of Matter ==================== Physical Property is a property of matter that is measured without changing a substance's chemical identity. - Extensive Property is a physical property of matter that depends on the amount of the substance. - Intensive Property is a physical prop...
Properties of Matter ==================== Physical Property is a property of matter that is measured without changing a substance's chemical identity. - Extensive Property is a physical property of matter that depends on the amount of the substance. - Intensive Property is a physical property of matter that is independent of the amount of a substance. A table with text on it Description automatically generated Chemical Property is an observed property when matter undergoes a change. The change is characterized by a change in identity and a change in composition. Examples of Chemical Property: - Flammability - Reactivity - Enthalpy - Atomic Stability Formulas Of Common Substances Chemical Formula --the symbolic expression of elements or compounds. It shows the number of atoms involved. Substance -- a form of matter with a fixed composition. Consumer Products Consumer product is the final good that is bought by individuals or households for personal use. In other words, consumer products are goods that are bought for consumption by the average consumer. [Isopropyl or Ethyl Alcohol?]{.smallcaps} Isopropyl alcohol is effective against viruses at 40% -- 60%. Ethyl alcohol is more effective at 70% -- 90%. [Ascorbic Acid or Sodium Ascorbate?]{.smallcaps} Ascorbic acid can increase the pH levels in your stomach and may trigger hyperacidity for those who are suffering from it. Sodium ascorbate help increase our sodium levels and prevents increase in acidity levels. Separation Techniques ===================== The earth is full of different mixtures which are present on land, water and air. They play important roles in our life because of their uses in the filed agriculture, health, industries and even to our practical living. However, substances in their mixture forms are not always the ideal substances. Thus, some mixture must undergo separation in order to breakdown its components for our ideal use. Mixtures A combination of two or more substances bound physically or chemically. - Homogeneous Mixture composed of only one phase; no visible boundary. - Heterogeneous Mixture composed of 2 or more phases; visible boundaries. A homogeneous mixture is called a SOLUTION. A solution is the combination of a solute and a solvent. The solute is the substance dissolved by the solvent. The solvent is the dissolving medium. Separation Of Homogeneous Mixtures Evaporation - A separation process that involves the evaporation and condensation of a liquid solvent from a solution. Chromatography - A process that involves separating a solid solute of a mixture between a mobile and stationary phase. Distillation - A process that involves the separation of a liquid solvent from a solid solute by the action of heat. Separation Of Heterogeneous Mixtures Sedimentation and Decantation - A process that involves the separation of an insoluble solute from a solvent. Filtration - A process that involves the separation of an insoluble solute from a solvent using a filter medium. Sieving - A separation process that involves the separation of smaller particles from bigger particles using a sieve. The Atom ======== Proton -- positively-charged sub-particle. Neutron -- neutral sub-particle;no charge Nucleus -- central core of the atom that houses the protons and neutrons. Electron -- negatively-charged sub-particle. ![A diagram of a number of electrons Description automatically generated](media/image2.png) A diagram of a mass number Description automatically generated Isotopes ======== The word isotope was derived from Greek words isos and topos which means "the same place." Isotopes are atoms of the same element having different mass numbers (different number of neutrons) ![A table with numbers and symbols](media/image4.png) Used in radiation therapy toprevent cancer. ![](media/image6.png)Used to study metabolism changes in patients with diabetes, gout and anemia. Used in molecular imaging of biological and biochemical processes. ![](media/image8.png) Used to help the doctor diagnose certain types of cancer. Chemical Formulas ================= A diagram of a person with a graph [Dalton's Atomic Theory]{.smallcaps} Molecules are composed of atoms of more than one element, combined in definite ratios with whole number values. During a chemical reaction, atoms combine, separate, or rearrange. No atoms are created, and no atoms disappear. Atom + Atom = Molecule Element + Element = Compound A chemical formula provides two important pieces of information: Element Symbols - the elements that make up the compound. Numerical Subscripts - the number of atoms of each element that are present in a compound. C12H22O11 (table sugar) Element Symbol Subscript Types Of Chemical Formulas Molecular Formula - Shows the actual number of atoms in a compound. Empirical Formula - Shows the simplest whole-number ratio of the atoms in a compound. Structural Formula - Shows how the atoms in a molecule are bonded to each other. Structural Formula A structural formula is a graphic representation of the molecular structure of a compound, showing how the atoms are possibly arranged in the real three-dimensional space. The chemical bonding within the molecule is also shown, either explicitly or implicitly. In deciding on how to write the chemical formula or name of a compound, identify first whether the compound is ionic or covalent. Ionic Compound -- composed of a cation and an anion. The cation is usually a metal, and the anion is a nonmental. Ionic compounds are formed by electron transfer from the cation to the anion. - Cation -- Positively-charged specie. It is formed when an atom loses electron(s). - Anion -- Negatively-charged specie. It is formed when an atom gains electron(s). ![A diagram of a periodic table Description automatically generated](media/image10.png) [Classification of Ionic Compounds]{.smallcaps} A table with chemical formulas Description automatically generated ![A chart of chemical formulas Description automatically generated](media/image12.png) Covalent Compound -- composed of two or more nonmetals. Covalent compounds are formed by electron pair sharing. Covalent compounds are named and written using a prefix system to denote the number of atoms. Examples: - Dinitrogen Monoxide (N2O) - Carbon Dioxide (CO2) - Sulfur Trichloride (SCl3) Writing the Chemical Formula of a Covalent Compound - Dinitrogen Tetroxide - N4O4 - Phosphorous Pentachloride - PCl5 - Disulfur Dihydride - S2H2 +-----------------------------------+-----------------------------------+ | Chemical Name | Chemical Formula | +===================================+===================================+ | Hydrochloric acid | HCI | | | | | Sulfuric acid | H2SO4 | | | | | Nitric acid | HNO3 | | | | | Carbonic acid | H2CO3 | | | | | Calcium hydroxide | Ca (OH)2 | | | | | Methane | CH4 | | | | | Aluminum oxide | Al203 | | | | | Sucrose | C12H22O11 | | | | | Ethanol | CH3CH2OH | +-----------------------------------+-----------------------------------+ Do You Know? Each hydrogen atom in your body is likely 13.5 billion years old as they were created at the birth of the universe. Molar Mass ========== The mass in grams of a 1 mol of a substance. The molar mass of an element is numerically equal to the atomic mass of the element atomic mass units. Unit: g/mo Percentage Composition ====================== EMPIRICAL FORMULA ================= A chemical formula that shows the composition of a compound in terms of the relative numbers and kinds of atoms in the simplest ratio. Is the simplest formula for a compound which is defined as the ratio of subscripts of the smallest possible whole number of the elements present in the formula. It is also known as the simplest formula. [Analysis of a 10.15g sample of a compound known to contain only phosphorous and oxygen indicates a phosphorous content of 4.433g. What is the empirical formula of this compound?]{.smallcaps} Mass of phosphorous = 4.433 g Mass of oxygen = mass of the sample -- mass of phosphorous Mass of oxygen = 10.15 g -- 4.433 g Mass of oxygen = 5.717 g ![A math equations with red lines Description automatically generated with medium confidence](media/image20.png) A screenshot of a cell phone Description automatically generated ![A table with numbers and symbols Description automatically generated with medium confidence](media/image22.png) MOLECULAR FORMULA ================= Remember that the empirical formula (EF) contains the smallest possible whole numbers that describe the atomic ratio. The molecular formula (MF) is the actual formula of a molecular compound. An EF may or may not be a correct molecular formula. The relationship between a compound's EF and its MF can be written as follows. X (empirical formula) = molecular formula \ [\$\$X = \\frac{e\\text{xperimental\\ formula\\ mass}}{\\text{Empirical\\ formula\\ mass}}\$\$]{.math.display}\ [Example:]{.smallcaps} [In sample M, the EF of a compound of phosphorus and oxygen was found to be P2O5. Experimentation shows that the molar mass of this compound is 283.89 g/mol. What is the compound's MF?]{.smallcaps} A screenshot of a math formula Description automatically generated [An analysis of nicotine, one of more than 4000 chemicals found in the smoke of tobacco products. If the molar mass of nicotine is 162 g/mol, what is its molecular formula if its EF is C5H7N.]{.smallcaps} ![A white background with black text Description automatically generated](media/image24.png) A screenshot of a math formula Description automatically generated Write And Balanced Chemical Equations ===================================== Chemical Reaction - Is a process in which at least one substance is produced as a result of chemical change. - Reactant-- substance that enter into a chemical reaction. - Product-- substance formed from the reaction. ![A group of black letters and numbers Description automatically generated](media/image26.png) Chemical equation = is a symbolic representation of a chemical reaction. It uses symbols and formulas to describe the changes that occur in the reaction. [Different Symbols]{.smallcaps} = separates the reactants from the products; read as yields, produces, forms, liberates. = separates the reactants or products from each other. =indicates a gaseous product. =indicates the presence of precipitates. =indicates heating process. (s), (l), (g), (aq) = signifies solid, liquid, gas and aqueous reactants or products 2NaHCO3 = 2 before the NaHCO3 is called "coefficient". Rules In Writing Chemical Equation Always follow rules in writing formulas of the compound. Hence, following the crisscross rule, it must be NaCl, CaO, Na2SO4. An element that is gaseous at room temperature is represented by its natural molecular formula. ![A black text with black letters Description automatically generated](media/image28.png) Coefficient & Subscript A close-up of a text Description automatically generated Coefficient applies to the whole formula. Subscript, on the other hand, affects only the element to which it is written. 2NaHCO3 The coefficient multiplied by the subscript gives the total number of an element in a formula. Hence, the above notation denotes 2 mol NaHCO3; made up of 2 Na atoms, 2 H atoms, 2 C atoms, and 6 O atoms. 4H2 H= 8 atoms 4(NH2)4S N=16 atoms, H=32 atoms, S= 4 atoms [Antoine Lavoisier ]{.smallcaps} - French Chemist - He states that atoms can neither be created nor destroyed in a chemical reaction; therefore, equations must be balanced. - (Law of conservation of mass) Balancing Chemical Equation =========================== ![A diagram of a reaction Description automatically generated with medium confidence](media/image30.png) A diagram of a chemical reaction Description automatically generated ![A math equations with numbers and symbols Description automatically generated](media/image32.png) Types Of Chemical Reactions **[Combination Reaction ]{.smallcaps}** This is the type where two substances combine to form a single product. A + B → AB Example: 2Ca + O2 → 2CaO **[Decomposition Reaction]{.smallcaps}** It is a reaction where a single compound decomposes to two or more substances. AB → A + B Example: 2NaH → 2Na + H2 **[Single Replacement ]{.smallcaps}** This is a reaction wherein an active element takes the place of another element in a compound. A + BC → AC + B Example: Zn + 2HCl → ZnCl2 + H2 **[Double Decomposition Or Double Replacement]{.smallcaps}** Also called metathesis, this is a reaction wherein two compounds react to form two new compounds and involve exchange of ion pairs. AB + CD → AD + CB Example: AgNO3 + NaCl → AgCl + NaNO3 A diagram of chemical formulas Description automatically generated Mass Relationship in Chemical Reactions ======================================= Mole To Mole Calculation This type of calculation is needed to find out the amount of moles that have consumed or have reacted in a chemical reaction, given the number of moles of another reactant or product. [Example ]{.smallcaps} ![A text on a white background Description automatically generated](media/image34.png) A red line with black text and black text Description automatically generated with medium confidence ![A math equations on a white background Description automatically generated with medium confidence](media/image36.png) Mass To Mole Relationship It is used to predict the mole of reactant /product from a given mass of reactant /product. The process of solving mass-to-mole problem is as follows: A yellow sign with black text Description automatically generated Stoichiometric calculations for mass-to-mole problem. [Example]{.smallcaps} ![A black text on a white background Description automatically generated](media/image38.png) Solution (Mass→Mole→Mole) A screenshot of a math formula Description automatically generated Mole To Mass Relationship Is used to get the mass of a reactant /product from a given mole of another reactant/product. The process of solving mole-to-mass problem is as follows: ![](media/image40.png) Stoichiometric calculations for mole-to-mass problem. [Example]{.smallcaps} A black text with black text Description automatically generated Solution (Mole→Mole→Mass)![A math equations and formulas Description automatically generated with medium confidence](media/image42.png) Mass To Mass Relationship Generally, a mass-to-mass problem looks like this: Given this amount of reactant, how much product will be formed? The process of solving mass-to-mass problem is as follows: A group of yellow rectangles with a red arrow Description automatically generated Stoichiometric calculations for mass-to-mass problem. [Example]{.smallcaps} ![A math equations and formulas Description automatically generated with medium confidence](media/image44.png) A screenshot of a math test Description automatically generated with medium confidence Calculate percent yield and theoretical yield of the reaction ============================================================= Theoretical Yield Is the maximum amount of product that can be produced from a given amount of reactant. Actual Yield The measured amount of a product obtained from a reaction. Percentage Yield Is the ratio of actual yield to the theoretical yield. ![](media/image46.png) [Example]{.smallcaps} A text on a white background Description automatically generated ![A math equations and formulas Description automatically generated with medium confidence](media/image48.png) Solution (Mass To Mass) A screenshot of a math problem Description automatically generated [Example]{.smallcaps} ![A math equations and formulas Description automatically generated with medium confidence](media/image50.png) A screenshot of a math problem Description automatically generated Limiting And Excess Reagent/s ============================= **[Limiting Reactant]{.smallcaps}** The reactant that limits the amount of the other reactant that can combine and the amount of product that can form in a chemical reaction. **[Excess Reactant]{.smallcaps}** The substance that is not used up completely in a reaction. [Example]{.smallcaps} ![A black text on a white background Description automatically generated](media/image52.png) A math equations on a white background Description automatically generated![A math equations and formulas Description automatically generated with medium confidence](media/image54.png) [Example]{.smallcaps} A close-up of a text Description automatically generated ![A math equations and formulas Description automatically generated with medium confidence](media/image56.png) A screenshot of a math Description automatically generated ![A screenshot of a computer Description automatically generated](media/image58.png) [Example]{.smallcaps} A white paper with black text Description automatically generated ![A math equations and formulas Description automatically generated with medium confidence](media/image60.png) A math equations on a white background Description automatically generated with medium confidence ![A maths with numbers and formulas Description automatically generated with medium confidence](media/image62.png) A maths with numbers and formulas Description automatically generated with medium confidence GAS === **[Pressure]{.smallcaps}** ![](media/image64.png)Is defined as force exerted per unit area. It is expressed in the following equation. Pressure is not limited to the force exerted by gases in a closed container. Pressure is also exerted by the weight of the air in the atmosphere. This is called *atmospheric pressure*. **[Atmospheric Pressure]{.smallcaps}** Decreases with height: Atmospheric pressure decreases as altitude increases because the column of air above us becomes shorter and lighter the higher, we go in the atmosphere. Measured by Barometer: Atmospheric pressure is measured using a barometer, a mercury-filled glass tube closed at one end, invented by Evangelista Torricelli. **[1 Atmosphere (1 atm)]{.smallcaps}** Standard Atmospheric Pressure: 1 atm is the pressure that supports a column of mercury exactly 760 mm high at 0°C at sea level, also known as 760 mmHg. Torr: The value of 760 mmHg corresponds to 760 torr. SI Unit: The SI unit of pressure is the Pascal (Pa), defined as one newton per square meter. **1 Pa = 1 N/m²** **Temperature of Gases** ▪Is a measure of the average kinetic energy or motion of gas molecules. ▪Molecules of gas are in constant, random motion. ▪These molecules possess mass, momentum, and energy, where momentum is the product of its mass and velocity; specifically kinetic energy is half the mass times the square of the velocity. ![](media/image66.png)where mmm is the mass of the molecule and vvv is its velocity. Celsius (°C), Fahrenheit (°F), or Kelvin (K) GAS LAWS ======== Boyle's Law Robert Boyle (1627-1691) The pressure-volume relationship. For a given mass of gas at a constant temperature, the volume is inversely proportional to the pressure. Formula: P1V1 = P2V2 ▪P1 = initial pressure, V1 = initial volume ▪P2 = final pressure, V2 = final volume A math equations and numbers Description automatically generated with medium confidence Charles Law Jacques Charles (1746-1823) The temperature-volume relationship. For a given mass of gas at a constant pressure, the volume is directly proportional to the absolute temperature (K). ![A black text on a white background Description automatically generated](media/image68.png) V1 = initial volume, T1 = initial temperature V2 = final volume, T2 = final temperature A math equations and numbers Description automatically generated Gay-Lussac's Law Joseph Louis Gay-Lussac(1778-1850) The pressure-temperature relationship. For a given mass of a gas at constant volume, the pressure is directly proportional to the temperature. ![](media/image70.png) P1 = initial pressure, T1 = initial temperature P2 = final pressure, T2 = final temperature A math equations and formulas Description automatically generated with medium confidence Combined Gas Law A combination of Boyle's Law, Charle's Law and Gay-Lussac's Law. It states that for a given mass of gas, the volume is inversely proportional to pressure and directly proportional to absolute temperature. ![A diagram of mathematical equations Description automatically generated](media/image72.png) A math equations and numbers Description automatically generated with medium confidence