...09. Net Ionic Equations tutorial.doc Introduction to Net Ionic Equations This tutorial will give you an algorithm for writing net ionic equations for aqueous reactions in general chemistry. Knowledge of the solubility rules is necessary to complete this tutorial. A list of solubility rules is provided at the end of the tutorial for review. Net ionic equations are necessary in chemistry for several reasons: 1. They show only those species undergoing chemical change – “spectator” ions are removed. 2. They must be used in any equilibrium calculation. 3. They allow chemical reactions to be combined properly. 4. Used when balancing half-reactions in oxidation-reduction chemistry. To take a chemical reaction in molecular form and rewrite as a net ionic equation is straight forward if you follow the steps given below. We will cover each step in detail using a common gas forming reaction from chemistry 1A. 1. Write the correct reactant and products – DO NOT BALANCE! The first step is to write the correct chemical formulas for the reactants and products, DO NOT BALANCE. The reaction will be balanced once the net-ionic equation is complete. As an example reaction, we will look at the aqueous reaction of sodium carbonate with acetic acid. Na2CO3 + HC2H3O2 ! NaC2H3O2 + H2O + CO2 (skeleton equation) The above reaction is called the skeleton equation; it contains only the correct chemical formulas of each reactant and product. Do not balance this equation! 2. Add phase...
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...observations and predictions) 6. Post Lab: Part I : Single Replacement Reactions a. For every reaction that took place you must write the balanced chemical equation b. Which metal reacted the most? c. Rank your metals from more to least active Part II: Double replacement Reactions a. For every reaction where you observed precipitate, write the complete balanced molecular equation, the complete ionic equation and the net ionic equation; use the solubility rules to identify the precipitate and the states of matter of each substance participating in the reaction. b. Which cation produced the most number of precipitates? c. Write general rules of solubility that you observed. 7. Final Conclusion and error analysis To do Lab Report for Single and Double Replacement reactions : This is a formal lab report. It must be typed or written with blue or black ink. Make sure that you include the following: 1. Title 2. List of Materials 3. Safety that includes MSDS risk assessment for all the materials used ( instructions were given to you already and they are in Moodle) 4. Pre-lab questions 5. Data Table with the results obtained ( observations and predictions0 6. Post Lab: Part I : Single Replacement Reactions d. For every reaction that took place you must write the balanced chemical equation e. Which metal reacted the most? f. Rank your metals from more to least active Part...
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...their persons while taking an exam. Cell phones/PDAs are to be placed in bags/backpacks which will be kept at the back of the lecture hall. Students may leave cell phones/PDAs on the front bench of the lecture hall. Students who are caught using cell phones/PDAs during an exam will be ejected from the exam and will receive a score of zero. This violation will be reported to the Dean and the Vice-Provost who will then take the appropriate disciplinary action. Only pens/pencils and scientific calculators (non-programmable and non-graphing) are allowed to be with students during exams. Students are not allowed to take an exam in a lecture section in which they are not registered. Chapter 4 – sections 4.1 – 4.8 Given a balanced chemical equation, you should be able to calculate grams (or moles) of a product (or reactant) given the grams (or moles) of another product (or reactant). Remember: grams A ( moles A ( moles B ( grams B (p. 118). Practice Example 4.1...
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...Oxidation-reduction reactions (or redox) reactions, are a type of reaction in aqueous solutions that involves a transfer of electrons between two species. An oxidation-reduction reaction is any chemical reaction in which the oxidation number of a molecule, atom, or ion changes by gaining or losing an e-. They occur every day and are vital to some of the basic functions of life. Some examples include photosynthesis (within plants), respiration (within animals), combustion, and corrosion or rusting. To understand these types of reactions, you must first understand oxidation numbers or states. Rules for Assigning Oxidation States The oxidation number corresponds to the number of electrons, e-, that an atom loses, gains, or appears to use when joining with other atoms in compounds. When determining the Oxidation State of an atom there are seven guidelines to follow: 1. The Oxidation State of an individual atom is 0. 2. The total Oxidation State of all atoms in: a neutral species is 0 and in an ion is equal to the ion charge. 3. Group 1 metals have an Oxidation State of +1 and group 2 an Oxidation State of +2 4. The Oxidation State of fluorine is -1, when in compounds 5. Hydrogen generally has an Oxidation State of +1 in compounds 6. Oxygen generally has an Oxidation State of -2 in compounds 7. In binary metal compounds, group 17 elements have an Oxidation State of -1, group 16 of -2, and group 15 of -3. (Note: The sum of the oxidation states is equal...
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...Bryan Ralloma Jennifer Caraway CHEM 1405-034 April 9, 2014 Balancing and Classifying Synthesized Chemical Reactions Abstract During the experimentation, physical and chemical properties of unaltered elements/compounds were noted. The alteration of these physical and chemical properties, were understood to have defined chemical change. The experimental procedures were divided into five phases: Magnesium and Oxygen, Zinc and Copper(II) Sulfate, Metals and HCl, Reactions of Ionic Compounds, and the Sodium Carbonate and HCl. Different Reactions were noted for each respective phase. When necessary, a numerical coefficient would be added before the name of the formula on either the reactant's or product's side to achieve a balanced chemical equation. Introduction Explosion of fireworks, pharmaceutical drugs(medicine), and fuel, what do they have in common? A chemical reaction! Most of these chemical reactions naturally occur without us having the slightest idea on that they exist. The focus of this experiment is to differentiate and classify different types of chemical reactions, and be aware of the significance and importance of these chemical reactions in our lives. One of the primary methods to classifying a synthesized chemical reaction is determining if it came from a : Combination, Single Replacement, Double Replacement, Decomposition, or a Combustion Reaction. Physical and Chemical Properties of the unaltered substances were noted and recorded as it was believed to...
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...Answer the questions below. When you have finished, submit this assignment to your teacher by the due date for full credit. (8 points) |Score | | | 1. Part 2: Single-Displacement Reactions: For each four single-displacement reaction, describe what happened in each well. If a chemical reaction occurred, write a balanced equation for it. Then use the A, B symbols to write a general equation for a single-displacement reaction. Here are the chemical formulas of the reactants for each reaction: • zinc – Zn copper sulfate – CuSO4 • aluminum – Al copper sulfate – CuSO4 • zinc – Zn silver nitrate – Ag(NO3) • copper – Cu silver nitrate – Ag(NO3) Answer: (8 points) |Score | | | 2. Part 3: Double-Displacement Reactions: For each double-displacement reaction, describe what happened in each well, including the colors of any products that formed. If a chemical reaction occurred, write a balanced equation for it. Then use the A, B symbols to write a general equation for a double-displacement reaction. Here are the chemical formulas of the reactants for each reaction: • sodium chloride – NaCl copper sulfate – CuSO4 • sodium hydroxide – NaOH copper sulfate – CuSO4 • sodium phosphate – Na3PO4 copper sulfate – CuSO4 • sodium chloride – NaCl silver nitrate – AgNO3 • sodium hydroxide...
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...of atoms as 12.0g of carbon -> 6.022 x 10^23 (Avogadro’s number) * Avogadro’s number – 6.022 x 10^23 * How to determine how many atoms of each element is in a compound: * (moles or grams)(6.022x10^23)(Number of atoms/1molecule) * Molar mass - Molar mass is the weight of one mole (or 6.022 x 1023 molecules) of any chemical compounds. * Mass % of an element in a compound: * ((Number of atoms of element)(atomic weight))/(Formula weight) * Empirical formula – Gives the lowest whole number ratio of atoms of each element in a compound (Grams)/(atomic weight) --- divide by lowest number on all * Molecular formula – gives actual whole number ratio of atoms of each element in each compound. (Molecular formula weight)/(Empirical formula weight) x compound * Formulas from analysis: * Structured formula – a formula that shows the atoms of a compound, their relative positions, and the bonds between them. * Isomers – compounds with the same molecular formula, but different properties and different arrangements of atoms * Writing chemical equations (symbols) : * + adding 2 or more chemicals together * -> Yields (Products) * (arrow forward and backward) reaction in both directions (denotes equilibrium) * (arrow up) gas evolved * (arrow down) solid precipitate forms * (s), (l), (g) solid, liquid, gas * (aq) aqueous solution * (Triangle) heating the solution * Limiting...
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...CHAPTER 3 MASS RELATIONSHIPS IN CHEMICAL REACTIONS This chapter reviews the mole concept, balancing chemical equations, and stoichiometry. The topics covered in this chapter are: • Atomic mass and average atomic mass • A vogadro’ s number, mole, and molar mass • Percent composition calculations • Empirical and molecular formula determinations • Chemical equations, amount of reactant and product calculations • Limiting reagents and reaction yield calculations Take Note: It is absolutely essential that you master the mole concept to do well on the quantitative aspects of AP Chemistry!! When solving quantitative problems on the Free Response section of the AP exam, supporting work must be shown to receive credit. Using dimensional analysis is a very powerful technique in solving problems. Be sure to report your answer to the correct number of significant figures (see Chapter 1 in this review book). Atomic mass and average atomic mass Atomic mass is the mass of an atom in atomic mass units (amu). One amu is defined as 1/12 of one C-12 atom. The C-12 isotope has a mass of exactly 12.000 amu. The C-12 isotope provides the relative scale for the masses of the other elements. Average atomic mass is the value reported on the periodic table, which takes into account the various isotopes of an element and their respective frequencies. To calculate the average atomic mass of an element, add up the different masses of the isotopes (using amu) multiplied by each isotope’s abundance...
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...masses, moles, and percents within a chemical equation. ________________________________________ ________________________________________ What is a Chemical Equation? In chemistry, we use symbols to represent the various chemicals. Success in chemistry depends upon developing a strong familiarity with these basic symbols. For example, the symbol "C"represents an atom of carbon, and "H" represents an atom of hydrogen. To represent a molecule of table salt, sodium chloride, we would use the notation "NaCl", where "Na" represents sodium and "Cl" represents chlorine. We call chlorine "chloride" in this case because of its connection to sodium. You should have reviewed naming schemes, or nomenclature, in earlier readings. A chemical equation is an expression of a chemical process. For example: AgNO3(aq) + NaCl(aq) ---> AgCl(s) + NaNO3(aq) In this equation, AgNO3 is mixed with NaCl. The equation shows that the reactants (AgNO3 and NaCl) react through some process (--->) to form the products (AgCl and NaNO3). Since they undergo a chemical process, they are changed fundamentally. Often chemical equations are written showing the state that each substance is in. The (s) sign means that the compound is a solid. The (l) sign means the substance is a liquid. The (aq) sign stands for aqueous in water and means the compound is dissolved in water. Finally, the (g) sign means that the compound is a gas. Coefficients are used in all chemical equations to show the relative amounts of each...
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...Purpose How do we determine the reaction type and write a balanced equation for chemical reactions? Background Discussion There are many kinds of chemical reactions and several ways of classifying them. One popular and useful method is to classify reactions into five major types. These are: (1) synthesis, (2) decomposition, (3) single replacement, (4) double replacement, and (5) combustion. Most reactions can be put into one of these categories. In a synthesis reaction, two or more substances (elements or compounds) combine to form a more complex substance. A decomposition reaction is exactly the opposite of a synthesis reaction. In a decomposition reaction, a compound breaks down into two or more simpler substances (elements or simpler compounds.) In a single replacement reaction, one element in a compound is replaced by a more active element. In a double replacement reaction, the positive ions of two different ionic compounds can be thought of as “replacing each other.” Most replacement reactions (both single and double) take place in aqueous solutions containing free ions. In a double replacement reaction, one of the products must be removed from the solution as a precipitate, water, or an insoluble gas. A precipitate is a solid that is produced as a result of a chemical reaction in solution. As the precipitate separates from the solution, the solution appears cloudy. In a combustion reaction a substance combines with oxygen, releasing a large amount...
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...DESIGN Aspect 1: Problem: The problem is will there be a chemical reaction taken place that is able to be observed. Variables: Manipulated: The different chemicals we use for each reaction. Responding: The observation of the chemical properties to see if a new chemical has been formed while the reaction is taking place. Controlled: The surface area of the calcium solid, the volume of chemicals, and the intensity of the flame from the Bunsen burner. Aspect 2: Background Information: This experiment requires four reactions to be observed to answer the problem. Chemical reactions occur when bonds are broken apart and re-joined. To create a new chemical, the bonds have to combined together in a different formation. To be able to observe what happens, you can look for the chemical properties such as: heat is given off, change in odour, color change, can physically see a new substance, and bubbles. There are WHMIS labels on some of the chemicals so use with caution. Aspect 3: Materials: * * Test Tubes(2) * Test Tubes Racks * Beaker * Test Tube Tongs * Wire Gauze * tweezers * Bunsen Burner w/ Tygon Tubing * Graduated Cylinders(2) * Phenolphthalein- toxic with other effects, flammable * Steel wool * 5mL Cu(NO3)2(aq) - Toxic with other effects, corrosive, oxidizing * 5mL NaOH(aq)- corrosive * 5mL Na2CO3(aq) - no WHMIS symbols * 5mL CaCl2(aq)- Immediate...
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...Electrochemistry Electrochemistry is a branch of chemistry that studies chemical reactions which take place in a solution at the interface of an electron conductor (the electrode: a metal or a semiconductor) and an ionic conductor (the electrolyte). These reactions involve electron transfer between the electrode and the electrolyte or species in solution. If a chemical reaction is driven by an externally applied voltage, as in electrolysis, or if a voltage is created by a chemical reaction as in a battery, it is an electrochemical reaction. In contrast, chemical reactions where electrons are transferred between molecules are called oxidation-reduction (redox) reactions. In general, electrochemistry deals with situations where redox reactions are separated in space or time, connected by an external electric circuit. Principles Oxidation and reduction The term "redox" stands for reduction-oxidation. It refers to electrochemical processes involving electron transfer to or from a molecule or ion changing its oxidation state. This reaction can occur through the application of an external voltage or through the release of chemical energy. Oxidation and reduction describe the change of oxidation state that takes place in the atoms, ions or molecules involved in an electrochemical reaction. Formally, oxidation state is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic. An atom or ion that gives up an electron to another atom or...
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...confirm we set up a time with our contact teacher for the 21st to write the test. The test is a paper copy and you will be providing us with a formula sheet, periodic table and the polyatomic ion sheet. We are not permitted to bring any materials with us to the written test as everything will be provided. I appreciate the fact that you will be emailing us to let us know which formulas we must study and ensuring that we memorize the prefixes for the covalent compound naming. We reviewed a few examples for balancing equations practice and discussed using the lowest coefficient possible as well as following proper convention for symbols. We moved on to reviewing an example for writing word equations as well as percent composition. During the percent composition you ensured we understand each step must be included for full point in case of an error during our procedure. We finished the eChat reviewing empirical formulas as well molecular formulas and discussing stoichiometry and the chemical recipe of “club house stoichometry”. We worked through some questions of stoichometry as well as mass stoichometry. 2. What skills or concepts did you learn by participating in this eChat? The skills and concepts I learned by participating in this eChat were related to writing word problems. Part b, Question 1 stated “when beryllium chloride reacts with silver...
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...of random error they can be either positive( measure more than you actually do ) or negative errors( measure less then you usually do ) * Systematic error: always the same direction (either positive or negative) Precision and Accuracy * Precision : how reproducible each measurement is , how close each measurement is to the other measurements * Accuracy : how close the measured values are to the true value. Temperature Conversions (on the exam) Chemical Language * Elements (Na,Cl)- letters of the language * Chemical Formulas (NaCl)- words of the language Water Vs. Hydrogen Peroxide (on the exam) * The use of Hydrogen peroxide: nuclear, bomb, bleach hair,etc * Molecular formula : water: H2O, Hydrogen Peroxide : H2o2 * Empirical Formula: water HO, Hydrogen peroxide: HO * Structural Formula : water HOH, hydrogen peroxide: HOOH quetion: how many atoms of carbon, hydrogen, and oxygen are present in a single molucule of citric acid C3H5O(CO2H)3 Carbon: 6 Hydrogen :8 Oxygen: 7 Chemical Bonding * Bonds form between atoms when they share electrons * Different types of bonds: Ionic compounds: metal+nonmetal, Covalent compunds Naming Ionic Compounds Polyatomic Ions (see the syllabus) * Ions that are comprised of more than one atom; the atoms remain bound together. Naming COvalent Compounds The Mole * Def: the number of atoms contained in exactly 12g of carbon-12 * 1 mole= 6.022x10^23- avogadro's number (N) Mass-mole-number...
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...Dublin Institute of Technology | Combustion | Thermodynamics Laboratory | | Name: Shiyas Basheer Student Number: D10119909 Programme/Course: DT022/3 Group: A Date of lab: 09/04/2013 Abstract Table of Contents Abstract 1 Introduction and Procedure 3 Calculations 3 Theory 3 Mass Flow rate analysis 4 Exhaust Gas 6 Results 7 Conclusion 8 Reference 9 Equivalent ratio of a gas turbine Introduction and Procedure For this experiment, a two shaft gas turbine (ET792) was used. At the core of ET792 are a so-called gas generator and a free-running power turbine. The gas generator consists of a radial compressor, a combustion chamber and a radial turbine. The compressor and turbine are mounted on a shaft. The gas turbine works as an open cyclic process, with the ambient air being drawn out and fed back in. Intake and exhaust silencers reduce the noise in operation of the power turbine. The use of propane as the combustion gas ensures clean, odorless operation. A start-up fan is used to start the gas turbine. The air is compressed and fed to the combustion chamber. Before it enters the combustion chamber the air is slowed by means of a diffuser. The air is then split into primary and secondary. The primary air mixes and burns with the fuel and the secondary air cool the exhaust gases. Relevant measuring values are recorded by sensors and indicated on the display and control panel. The energy of the exhaust gas stream is either converted into mechanical...
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