...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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...Acids dissociate to different extents in aqueous solution. Acids that dissociate to a large extent are strong electrolytes and strong acids. In contrast, acids that dissociate only to a small extent are weak acids and weak electrolytes In a similar manner, bases can be strong or weak depending on the extent to which they dissociate and produce OH– ions in solution. Most metal hydroxides are strong electrolytes and strong bases. Ammonia, NH3, is a weak electrolyte and weak base. o BASES eg oxides and hydroxides are substances that react and neutralise acids to form salts and water. Bases which are soluble in water are called alkalis. Acids Some common acids are listed below: Name Hydrochloric acid Sulphuric acid Nitric acid Ethanoic (acetic) acid Methanoic (formic) acid Citric Acid Formula HCl H2SO4 HNO3 CH3COOH HCOOH C6H8O7 Strong/Weak Strong Strong Strong Weak Weak Weak Where is it found? The stomach, in the lab. Acid rain, car batteries, the lab. Acid rain, in the lab. Vinegar Ant & nettle stings, descalers Citrus fruits Acids taste sour (e.g....
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...1) Look up the chemical/health hazards for sulfur!. Main Routes of Exposure: Inhalation. • Inhalation: VERY TOXIC, can cause death. Can cause severe irritation of the nose and throat. At high concentrations: can cause life-threatening accumulation of fluid in the lungs (pulmonary edema). Symptoms may include coughing, shortness of breath, difficult breathing and tightness in the chest. A single exposure to a high concentration can cause a long-lasting condition like asthma. If this occurs, many things like other chemicals or cold temperatures can easily irritate the airways. Symptoms may include shortness of breath, tightness in the chest and wheezing. {Reactive Airways Dysfunction Syndrome (RADS)}. • Skin Contact: CORROSIVE. The gas irritates or burns the skin. Permanent scarring can result. Direct contact with the liquefied gas can chill or freeze the skin (frostbite). Symptoms of mild frostbite include numbness, prickling and itching. Symptoms of more severe frostbite include a burning sensation and stiffness. The skin may become waxy white or yellow. Blistering, tissue death and infection may develop in severe cases. • Eye Contact: CORROSIVE. The gas irritates or burns the eyes. Permanent damage including blindness can result. Direct contact with the liquefied gas can freeze the eye. Permanent eye damage or blindness can result. • Ingestion: Not a relevant route of exposure (gas). • Effects of Long-Term (Chronic) Exposure: May harm the respiratory system. Can irritate...
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...molecules together. There are many tests that can be performed to determine whether a molecule contains covalent or ionic bonds, and three of these tests will be utilized in this lab. The compounds will be tested for their solubility and conductivity in water, and their melting points will also be determined. Covalent compounds usually do not conduct electricity in water and have relatively low melting points. Ionic compounds are usually conductive in water and have very high melting points. Using data collected from these tests, bonds can be classified as covalent or ionic. Guiding Questions: Please answer the following questions before beginning the lab. 1. A compound has a melting point of 92 oC, does not dissolve in water, and does not conduct electricity in water. What type of compound is this? 2. A compound has a very high melting point, does dissolve in water, and conducts electricity in water. What type of compound is this? Equipment/Materials: Acetylsalicylic acid Capillary tubes Calcium carbonate Conductivity apparatus Deionized water Dextrose Digital Thermometer Disposable pipet Dropping Tube Magnesium sulfate Mel-Temps Naphthalene Scoopula Sodium chloride Stirring rod Urea Wash bottle of DI water Well plate Zinc oxide Safety: Goggles should be worn in the lab. The parts on the top of the Mel-Temp are HOT while it is...
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...We recently did two labs where we were given the task of observing single-replacement and double-replacement reactions. This paper has background information on the different types of chemical reactions, as well as the chemistry behind the two reactions we observed in lab. A chemical reaction is a process that is characterized by a chemical change in which the reactants (starting products) are different from the products. Chemical reactions involve the breaking of old bonds and the formation of new bonds. They can result in the formation of precipitates, changes in color, production or absorption of heat, or formation of gas bubbles. Chemical reactions can be placed in the following five categories: (i) synthesis (ii) decomposition...
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...should be carried out in a water bath at 95oC. Direct heating of test-tubes should not be taking place. Apparatus & Equipments: Test tubes Test tube rack Boling tubes Wooden holder Water bath, 95oC Spatula Materials: Iodine 0.1 M hydrochloric acid Sudan III Starch solution Corn oil Egg albumin 1% copper sulphate solution 1% sucrose solution 0.1 M Sodium hydroxide 1% glucose/fructose/lactose solution Absolute ethanol DCPIP (dichlorophenolindophenol) solution Ascorbic acid Introduction The nutrients in the food you eat supply your body with energy for growth and repair. These principle substances include carbohydrates, proteins, fats, minerals and vitamins. We can test for the presence of these important compounds in food by using chemical reagents that react in predictable ways in the presence of these nutrients. Please refer to the notes given above on: How to record qualitative data. (Marks will be awarded based on proper recording.) What to do if you don’t obtain the desired results. Flowchart Students will be allowed to proceed with the experiment only if they have come into the laboratory with a flowchart of the day’s experiment. Lab manual version 6_201505 FHSB1214 Biology I & FHSC1214 Fundamentals of Cell Biology 14 Procedures: Part 1: Identification of Carbohydrates (A) Test for reducing sugars The reducing sugars include all monosaccharide, such as glucose and fructose, and some disaccharides, such as maltose and lactose, using...
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...after 1982. The metal compositions of the coins are as follows according to The United States Mint. The penny is 2.5% CU/Balance zinc (copper plated zinc). The nickel is 25% nickel/balance CU (cupronickel). The dime is 8.33% balance CU (cupronickel). The quarter is 8.33% Balance CU (cupronickel). Tarnish on coins happen when the metal combines with oxygen. Oxidation, which causes tarnish, is a chemical reaction. Oxidation also happens with reduction, which is when something gains electrons. pH (on the pH scale) stands for “the power of “H”, or hydrogen. The lower something is on the pH scale, the higher its acidity. Rust can weaken a coin or any other metal material. The green patches on coins are called copper oxide. It is caused by oxidation. When an acid reacts with tarnish, it makes the coins shiny. In order for oxidation to occur, the air has to be damp. In my experiment I used specific solutions to clean coins. Lemon juice has a ph of 2.2. Baking Soda has a pH of 8.4. Water has a Ph of 7. Orange juice has a Ph of 3.70. Cola has a Ph of 3.18. Dishwashing liquid has a pH of 7.80. Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are alkaline or basic. Pure water is neutral and isn’t an acid or a base. pH is an important measurement used in various medical, biological, chemical, environmental, and nutritional labs. pH standards are determined using a concentration cell with transference, by measuring the potential difference between a hydrogen...
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...Coordinator : Dr Chee Swee Yong Lecturers : Ms Chang Chew Cheen, Dr Chee Swee Yong, Dr Lim Tuck Meng, Dr Sim Yoke Leng |Lab group |Lab A |Lab B | |Venue |D012A |D012B | |Monday @ 9.00 am – 11.30 am |P5 |P1 | |Monday @ 3.00 pm – 5.30 pm |P2 |P3 | |Wednesday @ 9.00 am – 11.30 am |P3 |P4 | |Wednesday @ 3.00 pm – 5.30 pm |P1 |P2 | |Thursday @ 3.00 pm – 5.30 pm |P4 |P5 | |Week |Experiment |Lab group |Lecturer | |1 |Briefing by HoD |Lab A/ Lab B |Dr Sim KM | | |Expt 1: Investigating the properties of Period 3 oxides |Lab A |Dr Chee SY | | | | | ...
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...Lab Report for Experiment #4 Physical and Chemical Properties and Changes Student's Name __________ __________ Date of Experiment ___ _________ Date Report Submitted _________________ Title: (copy from lab, 1 point) Purpose: (copy from lab, 1 point) Changes to the Procedure by Instructors: 1. Do not test the odor of the samples. 2. In this lab the test tubes can get very dirty and cleaning is difficult. Your test tube may break, but don’t worry about it you will not need them again this term. Dispose carefully in the trash. Have you made any changes to the procedure? Please explain: Fill out the data sheet (page 3) for the experiment and answer the questions. Note: read the lab introduction for clarification on the difference between physical and chemical changes. Remember that a physical change often occurs during a chemical change, but a chemical change does not always happen when a physical change occurs. If you still have questions ask your instructor. From experiment # 1 we learned that a chemical change results in a color change, the formation of bubbles, the formation of a precipitate, or a change of temperature. Keep that in mind when you are deciding whether a physical or chemical change has occurred. Data Table (8 points) Read carefully before you begin your experiment! Be complete when writing your observations. One word observations are not usually complete. If there is a color change, include the color before and after. For...
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...Frequently Asked Questions (PAPER 6) 1) What is the purpose of ice or cold water? To cool down the gas so that it condenses and turns into a liquid. 2) when the gas collecting tube is upside down, give a property of this gas. It is less dense than air. 3) Why is a pencil used in drawing the origin line in chromatography? If pen was used, it will dissolve giving colors and so, the experiment won't be accurate. 4) When using ethanol, give a better apparatus arrangement, and why? Cover apparatus with a lid, because ethanol is volatile. 5) In the tests and observation tables, when in the first row, they tell you that upon heating condensation occurred, there will be a question asking what does this show about the solid? It is hydrated. 6) When copper is used in the test, and the answer is four marks, the best answer is: light blue precipitate (ppt) which is soluble in excess to form dark blue solution. 7) Why is this experiment done in a fume cupboard? It releases harmful gases that are poisonous. It is toxic. 8) Which result appears to be inaccurate? It is the point not appearing on the drawn graph, you read its x-axis and write it with a reason indicating that it doesn't occur in the graph. 9) Why should the solid be crushed? It increases surface area for a faster rate of reaction. 10) Why is the experiment made in a well-ventilated room? To prevent the burning of the substance. 11) Explain the term (decant). Filter/Pour the liquid leaving the solid alone. 12) Why is concentrated...
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...Brønsted · * Lewis · * Organic · * Strong · * Superbases · * Non-nucleophilic · * Weak | * v · * t · * e | In chemistry, an amphoteric species is a molecule or ion that can react as an acid as well as a base.[1] The word is derived from the Greek word amphoteroi (ἀμφότεροι) meaning "both". Many metals (such as zinc, tin, lead, aluminium, and beryllium) form amphoteric oxides or hydroxides. Amphoterism depends on the oxidation state of the oxide. One type of amphoteric species are amphiprotic molecules, which can either donate or accept a proton (H+). Examples include amino acids and proteins, which have amine and carboxylic acid groups, and self-ionizable compounds such as water and ammonia. Ampholytes are amphoteric molecules that contain both acidic and basic groups and will exist mostly as zwitterions in a certain range of pH. The pH at which the average charge is zero is known as the molecule's isoelectric point. Ampholytes are used to establish a stable pH gradient for use in isoelectric focusing. Contents [hide] * 1 Amphoteric oxides and hydroxides[2] * 2 Amphiprotic molecules * 2.1 Examples * 2.2 Not all amphoteric substances are amphiprotic * 3 See also * 4...
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...Practical 3 Investigation of Action of Saliva and Hydrochloric Acid in Two Carbohydrate Solution | Objective: 1. To show the action of saliva in two carbohydrate solutions. 2. To show the action of hydrochloric acid in two carbohydrate solutions. Apparatus & Equipment’s: Boiling tubes Metal test tube racks Beaker Graduated plastic dropper Water bath,~37°C Water bath,~95°C Stop watch Test tube holder Materials: Carbohydrate solution A Carbohydrate solution B Benedict’s solution 3M Hydrochloric acid 3M Sodium hydroxide Procedures: 1. Prepared two boiling tubes with containing 1 ml solution A and 1 ml solution B respectively. 1 ml Benedict’s solution was added to each tube and heated both tubes together in the (~95°C) water bath for two minutes. Then, recorded the results in table 1. 2. Added a few drops of fresh solution A and B separately spaced on a white tile. On each solution, added 1-2 drops of iodine solution and mixed with pen cover. Recorded your observations in the table 1. 3. Pipetted 2 ml solution B into each of four boiling tubes. The tubes were labelled 1, 2, 3 and 4 respectively near mouth of tube. Labelled your group name. 4. Placed tubes 1 and 2 in a water bath of ~37°C. 5. Salivated into a small beaker until it reached about 5 ml. 6. At the same time, step (6) and (7) was to be done approximately. Measured out 4 ml of the saliva prepared in step (4) and pipetted 2 ml each into tubes 1 and 4. The contents of the tubes shook well to ensure...
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...CHAPTER 1 INTRODUCTION LPG consists of mixture of propane and butane which is highly flammable chemical. It is odourless gas due to which Ethanethiol is added as powerful odorant, so that leakage can be easily detected. We can detect the presence of dangerous LPG leakage in the cars, industrial sectors and residential premises using an Ideal Gas Sensor. We can easily integrate the LPG gas leakage detector unit into a unit that can sound an alarm or give a visual suggestion of the LPG concentration. The sensor used in this Project will have both admirable sensitivity and rapid response time. This sensor can also be used to sense other gases like iso-butane, propane, LNG and even cigarette smoke. The output of the sensor goes LOW as soon as the LPG sensor senses any gas leakage. This is detected by the microcontroller and the LED & buzzer are turned ON. After a delay of few milliseconds, the exhaust fan is also turned ON for throwing the gas out and a “GAS LEAKAGE” message is sent to a pre-defined mobile number using GSM Module. MQ-5 Semiconductor Sensor for Combustible Gas Sensitive material of MQ-5 gas sensor is SnO2, which with lower conductivity in clean air. When the target combustible gas exist, the sensors conductivity is Higher along with the gas concentration rising. We use simple electro-circuit, convert change of conductivity to correspond output signal of gas concentration. MQ-5 gas sensor has high sensitivity...
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...in bulk will contain more acetone still. Some stores sell pure acetone as well.[2] | Acetylene gas | C2H2 | Ethyne | Hardware store or Welding supply; "acetylene"By reaction of calcium carbide and water. | Acetylsalicylic acid | C9H8O4 | Aspirin | Pharmacy; "Aspirin" | Aluminium | Al | Aluminium | General; "aluminium foil"Fine art store; "metallic pigment"—powdered aluminiumFiberglass supply shop; powdered aluminium as a filler material.Refined from mined aluminum ore, or bauxite.Often coated with wax to reduce flammability. | Aluminium hydroxide | Al(OH)3 | alumina hydrate | General; "antacid tablets"—blended with magnesium hydroxideAntacid Tablets; Alu-cap, Amphojel, Dialume—100%Fine art supply: "thickening agent" | Aluminium oxide | Al2O3 | alumina | Welding/Industrial supply; "sandblasting sand"—graded sizes of crystals. Metal polishing compoundTelescope supply; grinding agent for optical componentsLapidary supply; rock polishing compound | Aluminium ammonium sulfate | AlNH4(SO4)2 | ammonium alum | General; "styptic pencils" for shavingFine art supply; mordant for dying and...
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...[pic] • What is an alloy? An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal (heat treatment) history. Alloys usually have different properties from those of the component elements. Alloy constituents are usually measured by mass. Alloys are usually classified as substitutional or interstitial alloys, depending on the atomic arrangement that forms the alloy. They can be further classified as homogeneous, consisting of a single phase, heterogeneous, consisting of two or more phases, or intermetallic, where there is no distinct boundary between phases Examples: • Bronze (tin, aluminium or other element) • Aluminium bronze (aluminium) • Arsenical bronze • Florentine bronze (aluminium or tin) • Gunmetal (tin, zinc) • Glucydur • Phosphor bronze (tin and phosphorus) • Ormolu (Gilt Bronze) (zinc) • Speculum metal (tin) [pic] 1. Steel Composition: (Iron and other metals such as carbon) Properties: Hard, Less Ductile & have high Tensile Strength. Applications: Steel is used widely in the construction of roads, railways, other infrastructure, appliances, and buildings. Most large modern structures, such as stadiums and skyscrapers, bridges, and airports, are supported by...
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