Introduction:
Sulphate ions are a part of the earth’s crust and usually occur in natural waters. Many sulphate compounds are readily soluble in water. Most of them originate from the oxidation of sulphate ores, the solution of gypsum and anhydrite, the presence of shales, particularly those rich in organic compounds, and the existence of industrial wastes. Atmospheric sulphur dioxide formed by the combustion of fossil fuels and emitted by the metallurgical roasting processes may also contribute to the sulphate compounds of water. Sulphur trioxide (SO3) produced by the photolytic oxidation of sulphur dioxide comes with water vapours to form sulphuric acid which is precipitated as acid rain or snow. Sulphur-bearing mineral are common in most
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(ii) Buffer B (required when the sample SO4 2- concentration is less than 10 mg / l): Dissolve 30 g MgCl2. 6H2O, 5 g sodium acetate, CH3COONa. 3 H2O, 1.0 g potassium nitrate KNO3, 0.111 g sodium sulphate, Na2SO4, and 20 ml acetic acid (99%) in 500 ml distilled water and make up 1000 ml. (iii) Barium Chloride …show more content…
R. grade) in distilled water and make up to 1000 ml. 1.0 ml = 100 µg SO4 2-
Preparation of blank, standard and sample solutions
• Take six 50 ml flasks (4 for standard, 1 for blank and 1 for sample).
• The standards are prepared at 5mg/L increments in 0-40 mg/L sulphate range. Beyond 40mg/L accuracy decreases and barium sulphate loses stability.
• To the fifth flask (sample flask) add sample
• To the sixth flask (blank flask) add only distilled water. Do not add barium chloride to it because absorbance for blank is taken to correct for sample color and turbidity.
Procedure :-
(i) Use spectrophotometer at 420 nm.
(ii) Measure 100 ml sample in 250 ml Erlenmeyer flask
(iii) Add 20 ml buffer solution (A or B) and mix on a magnetic stirrer approach
(iv)While stirring, add a spoonful of barium chloride BaCl2 crystals and start observing time immediately. (v) Stir for 60 ± 2 sec at a constant speed. (vi) Immediately, take reading at 420 nm. The value of blank sample should be deducted from all the standard and sample reading to get final
Coursework Equipment List • Boiling tubes (8) I will use these because this is where I will mix both the sodium carbonate and the strontium nitrate in order to form the precipitate. I need 8 because I am going to add 8 different amounts of strontium nitrate (1-8cm³) to the 8cm³of sodium carbonate. • Measuring cylinder (1) I will use this to measure the 8cm³ of sodium carbonate and the varying amounts of strontium nitrate to put into the test tubes. • Sodium Carbonate (enough to fill 8 boiling tubes with 8cm³/64cm³)
In this lab we were trying to figure out if Salt Creek and Barker Lake had the correct chemical balances to sustain catfish for the years coming. In order to find this out, we tested the water using a Hach Water Testing Kit. Inside were dissolved oxygen reagent powder pillows 1, 2 and 3 which we added and mixed into our sample water to prepare it for testing. Then we added droplets of Sodium Thiosulphate Solution into the prepared water too see how much dissolved oxygen parts per million were in the water. Our independent variable in this experiment was the 5 different testing sites that we went to for water samples.
The anion tests followed the cation tests. To test for the presence of the chloride (Cl-) anion, a small scoop of the unknown compound was mixed with 1 mL of water in a test tube to create a solution. Then, 1 mL of 6 M nitric acid (HNO3) and 1 mL of silver nitrate (Ag(NO3)2) solution were added to the test tube to see if a white precipitate formed. To test for the presence of the sulfate (SO42-) anion, a small scoop of the unknown compound was mixed with 1 mL of water in a test tube to create a solution. Then, 1 mL of 6 M hydrochloric acid (HCl) and 1 mL of barium chloride (BaCl2) solution were added to the test tube to see if a white precipitate formed.
After obtaining an homogeneous mixture, the flask was placed in an ice bath during five minutes next to a graduated cylinder containing 5.0 mL of concentrated sulfuric acid. The temperature of the ice bath was recorded to be 1.1 °C. Likewise, a second graduated cylinder containing 1.8 mL of nitric acid and 2.5 mL of sulfuric acid was immersed in the cold ice bath to keep the three different solutions at the same temperature. Thereafter, the cold 5.0 mL of H2SO4 were added to the erlenmeyer flask containing the acetanilide solution, which remained in the cold water for approximately another 4 minutes.
3mL of the liquid in each of the vials were added into cuvettes and measured in the spectrophotometer. Before each time point the photo spectrometer was zeroed using a cuvette with 3mL of distilled water. If any of the results were considered unusual the machine was zeroed again and the sample was retested. The results from the spectrophotometer test were recorded in a table. The experiment was repeated six times to gain a sample size of six.
Pat McGurrin October 24, 2015 Period #1 Honors Biology Mr. Dinunzio Murder and Meal Lab Analysis Procedure: 1.) Gather all materials: Safety goggles, 250ml beaker, water, hot-plate, test-tubes, paper bag tear, stomach contents, pipette, Biruet solution, Benedict’s solution, and Iodine solution. 2.) Put on safety glasses.
Paragraph 1 The objective of the experiment is to test; how will water temperature affect the rate of reaction of an alka-seltzer tablet? The dependent variable of the experiment is the dissolving time. When an alka-seltzer tablet starts to fizz it begins to dissolve, due to the citric acid and sodium bicarbonate the tablet contains (Clark, “Why does Alka-Seltzer fizz?).
11) After you have prepared the dilutions, clean the outsides of the cuvettes with a paper towel. 12) Place the blank tube (tube 0) in the spectrophotometer. Since distilled water has no color it will not absorb any light so the absorbance number would be zero and this done to test the absorbance scale on the Spectrophotometer for the purpose of having it calibrated correctly. 13) Set the spectrometer to a wavelength of 530 nanometers. 14) Place the cuvettes (numbers 1-6) with the appropriate substance and record it’s reading in the data table.
Rediet Legese iLab Week # 6 CRUDE OIL DISTILLATION Introduction: The aim of this week lab experiment is to experiment distill crude oil and to check how temperature determine the chemical properties of crude oil plus how the boiling point can also show physical properties. They are two major finding in this experiment. he first finding was the point at which the raw petroleum is heated to the point of boiling, at 275 0C, the gas and kerosene oil are refined, however the oil (lubricant ) stays as an unrefined feature oil.
1. 150 ml of boiled water was poured into each of the three beakers labeled A, B, C. 2. Five tea bags were soaked for the time given by the manufacturer (two minutes) , in beaker A (Control). The teabags were immediately removed after the time elapsed. 3.
Properties of Ionic and Covalent Substances Lab Report Introduction The purpose of this lab was to determine which of the following substances: wax, sugar, and salt, are an ionic compound and which are a covalent compound. In order to accurately digest the experiments results, research of definitions of each relating led to the following information: ionic compounds are positive and negatively charged ions that experience attraction to each other and pull together in a cluster of ionic bonds; they are the strongest compound, are separated in high temperatures, and can be separated by polar water molecules. A covalent compound forms when two or more nonmetal atoms share valence electrons; covalent compounds are also
Properties of Ionic and Covalent Substances Lab Report Introduction The purpose of this lab was to determine which of the following substances: wax, sugar, and salt, are an ionic compound and which are a covalent compound. In order to accurately digest the experiments results, definitions of each relating factor were researched, leading to the following information: ionic compounds are positive and negatively charged ions that experience attraction to each other and pull together in a cluster of ionic bonds; they are the strongest compound, are separated in high temperatures, and can be separated by polar water molecules. A covalent compound is formed when two or more nonmetal atoms share valence electrons; covalent compounds are also categorized into two sections: polar covalent and nonpolar covalent. Furthermore, polar covalent compounds dissolve in water, while nonpolar covalent compounds do not.
Buffer solutions of pH 4 and 7 6. Graduated cylinder - 100 mL 7. Volumetric flask with stopper - 250 mL 8. Two 100-mL beakers 9. Two 50-mL Burettes 10.
The chemical equation for this experiment is hydrochloric acid + sodium thiosulphate + deionised water (ranging from 25ml to 0ml in 5ml intervals) sodium chloride + deionised water (ranging from 25ml to 0ml in 5ml intervals) + sulphur dioxide + sulphur. As a scientific equation, this would be written out as, NA2S2O3 + 2HCL + H2O (ranging from 25ml to 0ml in
Abstract — This experiment was conducted to familiarize the students with the procedures regarding distillation—to be more precise, the separation of ethanol from an alcoholic beverage—using a distillation set-up consisting of boiling chips, a Bunsen burner, a condenser, a thermometer and several other materials. In the end, it was discovered that one may actually separate a homogeneous mixture, given that the components of said mixture differ in volatility and that they utilize a complete distillation set-up and follow laboratory safety rules and regulations. Keywords — Matter, homogeneous and hetereogeneous mixtures, distillation, volatility, boiling point I. INTRODUCTION There are typically two categories of matter, these are pure substances