...Electrochemical Cells Objective: The purpose of this lab is to construct various electrochemical cells and to measure to voltage generated. Observations: Part 1 | Voltage | Anode | Cathode | Zn vs. Ag | 1.370 | Zn | Ag | Zn vs. Cu | .983 | Zn | Cu | Zn vs. Fe | .525 | Zn | Fe | Zn vs. Mg | .617 | Mg | Zn | Zn vs. Pb | .470 | Zn | Pb | Anode | Cathode | Equation | Predicted V (E0) | Measured V (E0 Zn) | E0Zn - E0 | Fe | Ag | Fe + 2Ag+ ↔ Fe2+ + 2Ag | 2.04 | 1.7 | 0.34 | Fe | Pb | Fe + Pb2+ ↔ Fe2+ + Pb | .31 | .41 | 0.10 | Mg | Ag | Mg + 2Ag+ ↔ Mg2+ + 2Ag | 3.97 | 3.35 | 0.62 | Mg | Zn | Mg + Zn2+ ↔ Mg2+ + Zn | 1.61 | 1.68 | 0.07 | Mg | Pb | Mg + Pb2+ ↔ Mg2+ + Pb | 2.24 | 2.4 | 0.16 | Mg | Cu | Mg + Cu2+ ↔ Mg2+ + Cu | 2.71 | 2.95 | 0.24 | Part 2 | Voltage | Anode | Cathode | Zn (s)|Zn2+ (1.0 M) || Cu2+ (0.0010 M)|Cu(s) | 0.909 | Zn | Cu | Equation for Cell Reaction | Predicted V | Measured V | Zn(s) + Cu2+(aq) ↔ Zn2+(aq) + Cu(s) | 1.19 | 0.909 | E = 1.1 V – (0.0592 V) / (2 mol) log (1.0 * 0.001) E = 1.1 + .0888 E = 1.19 V Part 3 | Voltage | Anode | Cathode | Zn (s)|Zn2+ (1.0 M) || Ag+ (unknown M)|Ag(s) | 1.743 | Zn | Ag | Equation for Cell Reaction | Calc [Ag+] | Calc Ksp AgCl | Ksp AgCl | Zn(s) + 2Ag+(aq) ↔ 2Ag(s) + Zn2+(aq) | 8.11 x 10-4 | 6.57 x 10-7 | 1.6 X 10-10 | E = E0 – (0.0592)/n log (Q) 1.743 V = 1.56 V – (0.0592 V) / (2 mol) log ([Zn][Ag+]2) (0.0592 V) / (2 mol) log ([Zn ][Ag+]2) = 1.56 V - 1.743...
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...Organic Chemistry Laboratory – CH 200L (2012 – 2013) 2A-BC Group 4 Experiment 1 Title of the Experiment Juan C. dela Cruz*, Pedro R. Reyes and Pablo S. Santos Department of Biochemistry, Faculty of Pharmacy University of Santo Tomas, Espana Street, Manila 1008 Date Submitted: ------------------------------------------------- Abstract The atoms in a compound are held together by a chemical bond. There are two types of chemical bond: ionic and covalent bond. An ionic or electrovalent bond results from the electrostatic attraction between metal and non-metal atoms by the transfer of electrons. _____________________________________________________________________________________ Introduction The atoms in a compound are held together by a chemical bond. There are two types of chemical bond: ionic and covalent bond. An ionic or electrovalent bond results from the electrostatic attraction between metal and non-metal atoms by the transfer of electrons. One example is the formation of bond between a sodium metal atom and a chlorine non-metal atom [1]. In contrast, covalent bond involves the sharing of valence electrons between non-metal atoms. A covalent bond becomes polar when there is unequal sharing of bonding electrons. This happens when the elements involved in the bond has a significant difference in their electronegativity, such as in hydrochloric acid, HCl. Equal distribution of bonding electrons leads to the formation of a non-polar covalent bond. ...
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...Dehydration Paper SCI/241 October 27, 2012 Water consumption is important to the body in order to maintain optimum health and function properly. The content of this paper will look at a few of the functions of water in the body and what can happen if enough water is not taken in, resulting in dehydration. Following the functions of water, I will discuss dehydration and its stages and symptoms. I will also cover the essential electrolytes in the body, sodium, potassium, and chloride their location, functions, intake recommendations, and the dangers of taking in too much of each. Alcohol and caffeine can have a negative effect on how the body uses water, so I will discuss and explain how both of these substances affect water in the body. Lastly, this paper will discuss ways to avoid becoming dehydrated. Water makes up over half of our body weight. In men, it is approximately 60 percent of their body weight and for women it is approximately 50 percent (Grosvenor & Smolin, 2006). Some of the main functions of water in the body are to help lubricate joints, regulates body temperature, and helps remove waste from the body and aids in the digestion process. When a person experiences joint pain, it is a sign of lack of water. Cartilage within the joints is about 80 percent water and provides a smooth surface for the joints to move on, but that is only the case if enough water is consumed. Lack of water means less lubrication for the joints causing friction...
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...CHEMESTRY LAB SUBJECT: CHEMESTRY TEACHER: MISS MUGANAMBUGA STUDENT: Levi Blaides TITLE: Investigating the properties of ionic and covalent substances INTRODUCTION: Certain characteristics such as solubility polar and non-polar solvents, melting point and conduction of electricity can be used to distinguish between ionic and covalent substances. AIM: To determine whether a substances is ionic or covalent in nature by observing its melting point, solubility and conductivity. APPARATUS/MATERIALS SODIUM CHLORIDE, SUCROSE, NAPTHALENE, COPPER (II) OXIDE, CALCIUM AND COPPER (II) SULPHATE ,6 TEST TUBES ,6 SPATULAS ,TEST TUBE HOLDER ,BUNSEN BURNER ,2 (100CM3) BEAKERS ,LOW VOLTAGE BATTERY ,CONNECTING WIRES ,ELECTRODES ,CURRENT DETECTING DEVICES METHOD: Two spatulas of naphthalene were placed in two test tubes heated for about one minute , gently at first then strongly until no further change occurred. Procedure was repeated and characteristics were record and it was stated whether the substances were: A) DOES NOT MELT AT THE TEMPERATURE OF THE BURNER. B) MELTS WITHOUT DECOMPOSITION WHEN GREATLY HEATED C) MELTS WITHOUT DECOMPOSITION WHEN STRONGLY HEATED D) DECOMPOSES WHEN HEATED. SOLUBILITY: Two beakers were filled, one with 50ml of ethanol and the other with 50 ml of distilled water. Two cups of distilled water were added and two spatulas of naphthalene and stir. Observations were recorded by stating if the substance was: * IS-INSOLUBLE ...
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...water and because of that all the essential functions of every single cell in our body are carried out in the presence of the universal solvent. A person can call it metabolism, flushing out of, toxic wastes, delivery of nutrients to the cells and also heat to transfer. When you feel hot, you grab a glass of water and you feel better. When you have some food, you take water (or some other liquid) with it, when you sweat during exercise or a steam bath, you feel good because along sweat is essentially water with waste being flushed out of your body. The enzymatic reactions in the cells are also dependent on water. Water is essential to maintain body's homeostasis. If normal water levels aren't maintained, it will affect the osmotic pressure, ion homeostasis and plasma/blood volume as well. Also it is required to excrete waste products from our body (E.g.; urine) and for the regulation of metabolic activities such as enzyme activation. Therefore, water is essential to maintain the body in its normal state. “Water serves many curative functions even in our day-to-day life. In fact, water is very essential for maintaining the proper functioning of our body and sustaining us. It makes up more than half of our body weight and caters to the requirements of various bodily needs. Deficiency of water in the body can affect various functions and in severe conditions might also lead to death. Effects of Water Deficiency * Low blood pressure * Clotting of blood * Kidney malfunction ...
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...Dehydration 1 Francia Moss SCI/241 February 19, 2012 Rebecca Gillaspy Dehydration 2 Dehydration is defined as the lack of the retaining of fluid that is needed to be in the human body. Our body is very sensitive and when it needs something that is missing, then we are alerted by its need with a prompt reaction from the body. Dehydration believe it or not can be mild or moderate and even severe depending on how much of fluid the body is missing. One must be cautious when the body goes into a severe mode of the lack of fluid. According to “Medline Plus” being dehydrated can also be life threaten if it’s really serious. We as people tend to slack on not drinking the amount of clear fluid that is required to keep us from being dehydrated. Instead we mostly drink other fluids that are no good for the body and doesn’t help the body like it should. Water is known to be the best fluid and safer fluid for the body; in fact water will restore the body’s energy when it’s lost from being productive. Water is very essential to our health in many ways, it helps with our reproductive system, it prevents us from being dehydrated, it helps bring the supply of oxygen to our cells, it makes up more than two thirds of the human body weight, and without water, we would die in a few days. All of the cell and organs in our body cannot work without the use of water in our body. The human brain is made up of 95% of water, blood is 82% and our lungs hold up about 90%...
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...2. Imagine that, as an employee of a pharmaceutical company, you are working on an H-K-ATPase. It is the enzyme that pumps acid into the stomach to help in digestion. You are trying to determine whether a compound will fit inside the pocket of this enzyme in order to inhibit the enzyme. To do so, you must know the molecular shape of the compound. Draw the Lewis structure and determine the molecular geometry of the following compounds that may fit into the active site of this enzyme: 0. CO2 0. KOH 0. NO3 0. HCN 3. Imagine that you work as a chemist in a battery manufacturing plant. You are asked to try a variety of substances that can be used to generate an ion potential necessary to produce electricity. Ionic compounds produce ions that can generate an ion potential when placed in an aqueous solution. Name the various compounds in the following table and label them as ionic or molecular: |Formula |Name...
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...inorganic reactions and phenomenon present in microbiological systems. The chemistry of the predominant biological elements of groups I to VII will be discussed. The students will explore the principles of inorganic chemical phenomenon including partially soluble substances, weak acids and bases, buffer systems and redox reactions. In addition, a basic understanding of the chemistry of the biologically important elements (H, C, N, O, K, Na, Ca, Mg, P, S, Cl and some transitional elements) will be explored. Course Learning Outcomes Upon successful completion, students will be able to: • Predict cation and anion concentrations of partially soluble solids dissolved in pure water and in a solution containing a common ion. • Apply knowledge of acids and bases in order to predict the pH of a solution containing a weak acid or base. • Demonstrate the use of common pH and redox indicators in microbiological media. • Select appropriate reagents to make a buffer having a desired pH. • Determine which compounds undergo the process of reduction and which undergo the process of oxidation. • Describe the basic chemistry of the predominant biologically important elements and their function(s) in microbiological systems. Dr. Andrew Baer Office Hours Monday: 10:30 am – 11:20 am Wednesday: 1:30 pm – 2:20 pm Thursday: 9:30 am – 10:20 am or by appointment Email: abaer@centennialcollege.ca Textbook: Hage, D.S and Carr J.D Analytical Chemistry and Quantitative Analysis...
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...* IONIC BONDING * With a sodium atom (NA) and a chlorine atom (CL) the sodium atom has a outer most shell of 1 electron and 7 vacancies. With chlorines outer most shell having 7 electrons and 1 vacancies, the 1 electron from the sodium atom will be stolen by the chlorine to satisfy both outer most shells of both atoms. * Because sodium has one more positive proton than negative electron it has a positive charge (+ion) and chloride has a – charge because it has an extra negative electron. * * HYDROGEN BONDING * Atoms that are sharing don’t really steal the electrons they just hog them which ends up giving them a partial positive and partial negative charge. * In a water molecule oxygen shares electrons with hydrogen BUT keeps the electron more often. (unequal sharing is referred to as a polar covalent bond) * Oxygen ends up with a partial negative charge, hydrogen ends up with a partial positive charge. * The partially charged oxygen is attracted to the partially charged hydrogen of a nearby water molecule. * * * Water is less dense as a solid, most dense as cold water. * Water is transparent * Water is also cohesive (like things attract. H2O -- H2O) and adhesive (unlike things sticking together H2O --- Glass). * High heat capacity: Absorbs heat without rising in temp. * Water is a great solvent: It dissolves things very well. * Water buffers PH well: Resist changes...
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...is an exothermic process. This is mainly due to the large amount of energy given out when the lattice forms. 1. Elements in their standard states. This is the energy zero of the diagram 2. Add in the atomisation of sodium. This is positive, drawn uphill. 3. Add in the atomisation of chlorine. This is positive, drawn uphill. 4. Add in the ionisation of sodium, also posstive, drawn uphill. 5. Add in the electron affinity of chlorine. This is negative drawn downhill 6. Add in the enthalpy of formation of sodium chloride negative= downhill. 7. The final unknown quantity is the lattice formation enthalpy of sodium chloride. The size of this is 788kjmol-1 from the diagram. Lattice energy is the change from separate ions to solid lattice and we must therefore go downhill so LE (Na+ + Cl) = 788kjmol-1. Trends in lattice...
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...omitted because it doesn't form an oxide. A quick summary of the trends The oxides The oxides we'll be looking at are: |Na2O |MgO |Al2O3 |SiO2 |P4O10 |SO3 |Cl2O7 | | | | | |P4O6 |SO2 |Cl2O | Those oxides in the top row are known as the highest oxides of the various elements. These are the oxides where the Period 3 elements are in their highest oxidation states. In these oxides, all the outer electrons in the Period 3 element are being involved in the bonding - from just the one with sodium, to all seven of chlorine's outer electrons. The structures The trend in structure is from the metallic oxides containing giant structures of ions on the left of the period via a giant covalent oxide (silicon dioxide) in the middle to molecular oxides on the right. Melting and boiling points The giant structures (the metal oxides and silicon dioxide) will have high melting and boiling points because a lot of energy is needed to break the strong bonds (ionic or covalent) operating in three dimensions. The oxides of phosphorus, sulphur and chlorine consist of individual molecules - some small and simple; others polymeric. The attractive forces between these molecules will be van der Waals dispersion and dipole-dipole interactions. These vary in size depending on the size, shape and polarity of the various molecules - but will always be much weaker than the ionic or covalent bonds...
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...AP Chemistry Summer Assignment Mr. Ronnenkamp Welcome to SPHS AP Chemistry!! You already have a background in chemistry from your General Chemistry class, but AP Chem is very different. Rather than memorizing how to do particular types of problems, you must really understand the chemistry and be able to apply it to different kinds of problems. AP Chemistry is a challenging course. To succeed, you must keep up with the assignments and be willing to spend time working through the material. Like all AP classes, AP Chem comes with a summer assignment. It is due the second day of class - August 25th - and will count as ½ of a test grade. ALL YOUR ANSWERS FOR THE SUMMER ASSIGNMENT SHOULD BE PUT ON ANOTHER SHEET OF PAPER!!!! We will then have a CLASS TEST on the SUMMER ASSIGNMENT ON 9/1/2015 (depending on schedule)!!! This class test will count as the second ½ of your first test grade. I check my e-mail frequently, so feel free to contact me if you are having problems doing the summer assignment. I can offer help via email. My e-mail address is: ronnenkampd@pcsb.org Please take the summer assignment seriously. Completing the summer assignment will allow you to enter AP Chemistry in August ready to succeed!!!! Each section of the summer assignment is referenced with web tutorials to help you if you have forgotten some of your General Chemistry, but feel free to use any good website. I will also be giving you access to an online textbook. ONLINE...
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...contained in a molecule of tetrodotoxin? What are the names of these elements? 0 Carbon, hydrogen, nitrogen, oxygen are the four elements found in 1 tetrodotoxin 3. What types of chemical bonds are found in this molecule? Describe the structure of those bonds. The chemical bond found in tetrodotoxin is a covalent bond, which are bonds that share electrons. 4. As mentioned in the case description, tetrodotoxin is a molecule that blocks voltage-gated sodium ion channels. Describe the structure of a sodium ion. The sodium ion has eleven protons and ten electrons, indicating that the first orbital shell has two electrons and the second shell has eight electrons (1s2 2s2 2p6) 5. the channel is a protein embedded in the plasma membrane of the neuron or muscle cell. as the membrane potential moves down the cell, this causes the channel to open and be selectively open for Na+ to pass through. when polarized, the channel is open and Na+ pass through causing depolarization of the channel, shutting it to further Na+ influx\ 6. Ion channels are primarily protein complexes specialized to fit a specific...
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...Task 1b Practical analysis The products of the practical were typical for an acid-base titration with carbonate, which are sodium chloride, carbon dioxide and water. The balanced equation for the practical is Na2CO3 + 2HCl = 2NaCl + CO2 +H2O. This is because the as you add the hydrochloric acid to the sodium carbonate the chlorine displaces the carbon and oxygen which then becomes carbon dioxide and water with the lone hydrogen. Ionic bonding is when a metal gives an electron(s) to a non-metal to form an ionic compound, the compound is held together by the electrostatic energy from the elements being polar after the swap of electrons. Covalent bonding is when non-metal atoms share electrons in order to have full outer shells. Sodium is in group one the alkali metals which are very reactive due to them having only one valent electron that can be easily lost in an ionic bond. Chlorine is in group seven the halogens which are also very reactive due to them all having seven valent electrons meaning that they can easily gain an electron in ionic bonding; both chlorine and sodium are in period three. Since chlorine has seven valent electrons and sodium only has one valent electron, sodium’s electron can easily form an ionic compound with chlorine by giving its free electron to chlorine. Carbon is a non-metal in the group 4 (period 2) meaning that it has 4 valent electrons. Oxygen is also a non-metal in group 6 (period 2) meaning that it has 6 valent electrons and needs to...
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...Group Electron Arrangement Number of Bonds and Lone Pairs 1A 7A 1 bond and no lone pairs H X 6A X = F, Cl, Br or I O O O 6A Version: 3/22/16 S 1 bond and 3 lone pairs in biological systems Oxygen generally has 2 bonds and 2 lone pairs, but may have one bond and 3 lone pairs in anions such as hydroxide, or 3 bonds and 1 lone pair in cations such as hydronium. Sulfur has 2 bonds and 2 lone pairs in biological systems. Page 1 of 8 Molecular Structures 5A N Nitrogen generally forms 3 bonds with 1 lone pair, but may form 4 bonds with no lone pairs in cations. N 5A 3- O O P O O 4A C Si In biological systems, phosphorus generally exists as the phosphate ion shown here where it forms 5 bonds with no lone pairs. Outside of biological systems, P sometimes behaves like N by forming 3 bonds with 1 lonepair. Carbon forms 4 bonds and no lone pairs. It is not stable with any other arrangement. Similarly,...
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