Aim Determination of total and carbonate hardness of tap water using titration technique. Eliminating total hardness with a Na+ ion-exchange softener. Reagents 0.1 M hydrochloric acid, 0,025 M and 0,005M trilon-B solution, buffer solution (NH4Cl + NH3∙H2O), indicators methyl red (mr) or methyl orange (mo) and chromogen black ET-00. Apparatus Conical flasks (250 ml, 500 ml), measuring cylinder (25 cm 3), burette (25 cm3), pipettes (100 cm3). Experimental Procedure A Determination of carbonate hardness 1. Rinse the 100 cm3 pipette 2...3 times with a small amount of the test water. Wash the conical flask with distilled water. Pipette 100 cm 3 of the test water and transfer it into the conical flask, add 3...4 drops of indicator mo or mr. 2. Prepare the burette – remove any air bubbles from the nozzle and fill with 0.1 M hydrochloric acid till zero (The lower meniscus has to coincide with the scales 0-notation). 3. Titrate with a 0.1 M hydrochloric acid solution, while swi
concentration (the standard solution) and pour it into the burette (α in figure 2.2). See that there are no air bubbles near the tip. Fill the burette until the 0-point of the scale. When measuring the level of the solution keep your eyes at the same level with the liquid level. The lower edge of the liquid level has to be at the 0 calibration mark (see figure 2.1). Work solutions are the solutions which are going to be used for pipetting or Figure 2.1 added from the burette. This step is necessary to ensure that the measuring of concentration is not changed by water or solvent of another concentration. 2. Use the pipette pump (c) on the pipette (figure 2.2, b). With the pipette, measure 10 cm3 of acid into a clean conical flask and add 2-4 drops of indicator ff (phenolphthalein). 3
Aim Determining the identity of an unknown metal. Measurement of gas volume, calculations with gases based on reaction equations. Substances 10% solution of hydrochloric acid, 5,0...10,0 mg piece of a metal. Equipment Apparatus for measuring the volume of gas, measuring cylinder (25 cm 3), funnel, filter paper, thermometer, barometer and hygrometer. Experimental procedure 1. The experimental apparatus (Figure 1) consists of two burettes connected with a rubber hose (a), which is filled with water. One burette is connected to a test tube (b), in which the metal reacts with the acid. 2. Preparation for the experiment. Remove the test tube and wash it carefully with distilled water. Firmly attach the test tube back. Adjust the burettes to the same height and check whether the water level (c) in both of the burettes is at the same height. Raise one of the bure
The systematic error: | 2= 41,41 g mol -44,0 g mol|=2,59 g mol The relative systematic error g 2,59 ×100 mol 2= =5,89 g 44,0 mol Kokkuvõte It is possible to find volume and molar masses of gases in laboratory environment. Also you can investigate relationship between temp., volume and pressure. As the errors are less than 10% then the results are acceptable. It is hard to improve the results because gases are not visible.
Aim To familiarize oneself with some more common instances of corrosion. Reagents Hydrochloric acid 0.1 M; sulphuric acid 0.1 M; zinc and aluminium granules; copper wire; solution of copper(II) sulphate; solution of copper(II) chloride; solution of iron(II) sulphate; solution of potassium hexacyanoferrate(III); zinc-plated iron sheet; tin-plated iron sheet; iron paper clips; solid NaCl; urotropin. Equipment Test tubes, small beaker (50 cm3), centrifuge tube. Experiments 1. Making of a galvanic pair 1.1. Place a zinc granule on the bottom of the centrifuge tube and pour solution of hydrochloric acid on top. Write down the equation of reaction which occurs. Which compound is the oxidant, which is the reductant? Zn+2 HCl ZnCl 2 + H 2 -¿ H 2 Oxidant is H: +¿+2 e ¿ 2 H¿ 2+ ¿ ¿ Reductant is Zn: -¿ Zn
library. I have to thank the anonymous creator of the file 2-stroke-guide_r2.zip. I felt I had to share the background and history of the quest. Perhaps it will help you enjoy this copy and in closing I would like to thank Gordon Jennings for the fine material and all the effort he put into the original publication. Computers and all the fine software have taken modifying and tuning two-strokes to a level higher that one could have imagined in 1973. A lesser work would have surely passed into “Nostalgia Heaven” long ago. On page 51 Gordon uses the term “One-Percenter”, the term refers to an American Motorcyclist association quote “that 99% of motorcyclists were law-abiding citizens, and the last one percent were outlaws”. ii iii FOREWARD Only ten years ago the two-stroke engine was widely and quite understandably
Tallinn University Natural and exact sciences Molecular Biochemistry and Ecology Maria Gnidenko Capillary electrophoresis Essay Supervisor: Kert Martma Tallinn 2015 Table of contents Acronyms and symbols used Introduction History and development Physical basis and principle of separation Elektrophoresis Electroosmotic flow Separation process Electrodispersion Various methods of separation Capillary zone�
keyway liistusoon micrometer mikromeeter CUTTING TOOLS Hacksaw is used for cutting metal. There are two types of hacksaw frames solid and adjustable. The solid type will only hold one size of blade; the adjustable type can be fitted with different length blades. Blades come in various pitches. The pitch represents the number of teeth per inch. The standard pitches are 14, 18, 24, and 32 teeth per inch. For general purpose work the 18 pitch is used. The 24 pitch is used for cutting thick wall tubing, pipe, copper, brass. The 32 pitch is used for thin wall tubing and sheet metal. Mini-Hacksaw Frame is used for difficult-to- reach positions. Tubing cutter is used for cutting tubes. The cutting of tubes with a tube cutter is more efficient than cutting with a hacksaw. Chisels are classified according to their points, the most common being flat, crosscut and pointed nose. Chisels are usually made of octagonal tool steel,
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