Characteristics of the oxide properties of sulfuric acid. Obsession with sodium thiosulfate. The speed of chemical reactions. Experiments B) Electrolysis of potassium iodide
atria thiosulfate Natrii thiosulfas
Na 2 S 2 0 3 -5H 2 0 M. m. 248.17
Sodium thiosulfate is not a natural product, but is synthetic.
In industry, sodium thiosulfate is obtained from gas production outlets. This method, regardless of the richness of the stages, is economically viable, since the raw material is the output of gas extraction, oxide, and lamp gas, which is created during the coking of coal.
The lamp should always be filled with water in the house, which is contained in clay, such as calcium hydroxide. When this happens, calcium sulfide comes out.
During the extraction process, calcium sulfide undergoes hydrolysis, and the reaction proceeds much differently with calcium hydrosulfide.
Calcium hydrosulfide, when oxidized by acid, reacts with calcium thiosulfate.
When calcium thiosulfate is fused with sodium sulfate or sodium carbonate, sodium thiosulfate Na 2 S 2 0 3 is obtained.
After evaporation, sodium thio-sulfate, which is a pharmacopoeial drug, is crystallized.
At first glance, sodium thiosulfate (II) is a barless crystal of salty-bitter relish. It’s really easy to break up by the water. At a temperature of 50 °C it melts in its crystallized water. The structure is characterized by thiosulfuric acid (I).
As is obvious from the formulas of these formulas, the oxidation stage of sulfur atoms is different in molecules. One atom of sulfur has an oxidation level of +6, another -2. The presence of sulfur atoms at different stages of oxidation indicates their power.
Thus, present in the S 2- molecule, sodium thiosulfate exhibits unique properties.
Like thiosulfuric acid itself, its salts do not have any toxic properties and are easily decomposed by the addition of acids and are as weak as vugol.
This power of sodium thiosulfate to decompose into acids from the visible sulfur is used to identify the drug. When sodium chlorohydronic acid thiosulfate is added to the solution, a cloudy stain due to the visible sulfur is avoided.
A reaction that is very characteristic of sodium thiosulfate is its destruction of nitrate. In this case, you can see a precipitate of white color (Sribla thiosulfate), which is liquid. When standing under the flow of water, the sediment turns black after seeing the sulfide of the cut.
When reacting with sodium thiosulfate nitrate, a black precipitate is formed, which indicates that the preparation is contaminated with sulfides, which when reacting with nitrate, results in a precipitate of sulfide .
The pure preparation, when used for dilution, cut off the dark nitrate without irritation.
As a reaction, vicoristan can also react with sodium thiosulfate and sodium chloride (III). When this occurs, the oxidation thiosulfate is formed in a violet color. The barkiness of the liquid is due to the renewal of the salt value to barbaric fermented salts (FeS 2 0 3 and FeS 4 0 6).
When interacting with sodium iodine, thiosulfate acts as a precursor. Accepting electrons from S 2 - iodine is converted to I -, and sodium thiosulfate is oxidized by iodine to sodium tetrathiate.
Chlorine is produced in a similar way in chlorine water.
When there is too much chlorine, the sulfur that is visible is oxidized to sulfuric acid.
This reaction was the basis for the use of sodium thiosulfate to remove chlorine from the first gases.
The preparation is not allowed to contain any compounds such as myshyac, selenium, carbonates, sulfates, sulfides, sulfites, calcium salts.
GF X allows the presence of houses of chlorides and salts of important metals at the boundaries of the glass.
The determination of sodium thiosulfate is carried out using the iodometric method, which is based on the reaction of its interaction with iodine. GF, instead of sodium thiosulfate, in the drug contains no less than 99% and no more than 102% (within the permissible range of vitrification of the drug).
The solution to sodium thiosulfate is based on its power to see the sirka. The drug is used as an antitear in case of poisoning by halogens, cyanogen and cyanodonic acid.
Potassium rhodanide, which is stabilized, is richer and less intense, lower potassium cyanide. Therefore, when using cyanohydronic acid or salts, sodium thiosulfate first helps to solidify. The drug may also become contaminated with the presence of ashes, mercury, or lead; In this case, non-eliminating sulfides are resolved.
Sodium thiosulfate is also used for allergic illnesses, arthritis, neuralgia internally in the form of 30% aqueous solution. In conjunction with zym GF X, add 30% sodium thiosulfate for injection (Solutio Natrii thiosulfatis 30% pro injectionibus).
Available in powders and in ampoules of 5, 10, 50 ml of 30% strength.
Sodium thiosulfate should be mixed with crystallization water, which vibrates easily, so keep the traces in a cool place, in well-sealed dark glass bottles, as the light will protect it when laid out. When standing, the faults become blurred from the gray that can be seen. This process occurs in the presence of carbon dioxide. Therefore, flasks or bottles containing sodium thiosulfate should be protected with a calcium chloride tube lined with sodium carbonate, which is used to clay them.
Zavdannya 866.
Write down the reaction to sodium thiosulfate. What is the stage of oxidation of the liquid in this mixture? Oxides or thiosulfate ion reveal the most important power? Apply a reaction.
Decision:
Rivalry of Obsession Reactions sodium thiosulfate:
a) Aqueous solution of sodium sulfite is boiled in the presence of sulfur, and then cooled, a crystalline hydrate appears sodium thiosulfate:
Na 2 SO 3 + S + 5H 2 O ↔ Na 2 S 2 O 3 . 5H2O.
The aqueous solution of sodium sulfite is boiled in the presence of sulfur, and then cooled, a crystalline hydrate of sodium thiosulfate appears.
b) Oxidation of polysulfides with acid:
2Na 2 S 5 + 3O 2 ↔ 2Na 2 S 2 O 3 +6S.
c) Removing sodium thiosulfate from the interaction of sulfur with meadow. The reaction proceeds with one-hour oxidation and renewal of the liquid:
4S + 6NaOH ↔ Na 2 S 2 O 3 + 2Na 2 S + 3H 2 O.
d) Direct interaction of sulfuric anhydride with sulfuric anhydride in the water medium. In order to pass both gases through a highly mixed mixture of sodium hydroxide until neutralized, sodium thiosulfate is created:
4SO 2 + 2H 2 S + 6NaOH ↔ 3Na 2 S 2 O 3 + 5H 2
Sulfur atoms that enter the thiosulfate warehouse exhibit different levels of oxidation; in one atom the oxidation state is +4, in the other 0. The thiosulfate ion S 2 O 3 2 exhibits the power of the descendant. Chlorine, bromine and other strong oxidizing agents oxidize it to the sulfate ion SO 4 2-, for example:
Interaction sodium thiosulfate with chlorine (extra charge):
Na 2 S 2 O 3 + 4Cl 2 + 5H 2 O ↔ 2H 2 SO 4 + 2NaCl + 6HCl
Ionic-molecular comparison:
S2O 3 2- + 4Cl 2 0 + 5H 2 O ↔ 2SO 4 2- + 8Cl - +10H+
Molecular form:
Na 2 S 2 O 3 + 4Cl 2 + 5H 2 O ↔ 2H 2 SO 4 + 2NaCl + 6HCl l
In this reaction, sodium thiosulfate acts as a catalyst, increasing the oxidation stage of one sulfur atom from 0 to +4, the other – from +4 to +6.
Under the action of a weak oxidizing agent, sodium thiosulfate is oxidized to a salt. tetrathionic acid H2S4O6.
Reaction between sodium thiosulfate and iodine:
2 Na 2 S 2 O 3 + I 2 ↔ Na 2 S 4 O 6 + 2NaI
Level of ion-molecular balance:
Ionic-molecular comparison:
2S 2 O 3 2- + I 2 0 ↔ S 4 O 6 2- + 2I -
Molecular form:
2Na 2 S 2 O 3 + I 2 ↔ Na 2 S 4 O 6 + 2NaI
In this reaction, sodium thiosulfate acts as a catalyst, increasing the oxidation stage of one sulfur atom from 0 to +4. When heated above 200 0C, sodium thiosulfate disintegrates according to the following scheme:
4Na 2 S 2 O 3Na 2 SO 4 + Na 2 S + 4S↓
In this case, an autoxidation-renewal reaction occurs.
Reactions of sulfuric acid
Zavdannya 867.
Scope of reactions: a) concentrated H 2 SO 4 with magnesium and scrap; b) diluted H 2 SO 4 from the liquid.
Decision:
a) 4Mg + 5H 2 SO 4 (conc.) → 4MgSO 4 + H 2 S) + 4H 2 O;
b) 2Ag + 2H 2 SO (conc.) → Ag 2 SO 4 + SO 2 + 2H 2 O;
c) Fe + H 2 SO 4 (dispersed) → FeSO 4 + H 2.
Zavdannya 868.
How many grams of sulfuric acid are needed to disintegrate 50 g of mercury? How long does it take to oxidize mercury? How can you use diluted sulfuric acid to disintegrate mercury?
Decision:
Rival reaction:
Level of ion-molecular balance:
Ionic-molecular comparison:
Hg + SO 4 2- + 4H + ↔ Hg 2+ + SO 2 + 2H 2 O
From the oxidation-renewal level, 1 mole of H2SO4 is consumed for the oxidation of 1 mole of Hg, so
200,5: 98 = 50: X; X = (98 . 50) / 200.5 = 24.44 rubles.
We know the mass of H2SO4 from the proportion:
200,5: (2 . 98) = 50: X; X = (2 . 98 . 50) / 200.5 = 48.88 rub.
Subject: 48.88 g; RUR 24.44 Mercury stands next to the water - then sulfuric acid is diluted with mercury. Also, to destroy mercury, it is necessary to take concentrated sulfuric acid.
Zavdannya 869.
How much sulfuric acid is required to disintegrate 40 g of nickel, if we take concentrated acid in one form and dilute acid in the other? What kind of sulfuric acid is used for the oxidation of nickel in skin lesions?
Decision:
Range of reactions:
a) Ni + 2H 2 SO 4 (conc.) → NiSO4 + SO2 + 2H2O;
b) Ni + H2SO4 (dispersed) → NiSO4 + H2.
We dissolve a mass of concentrated sulfuric acid, which is used for oxidation of 40 g of nickel in the following proportions:
58,7: (2 . 98) = 40:X; X = (2 . 98 . 40) / 58.7 = 133.56, g.
Now we dissolve the mass of diluted sulfuric acid, which is used for the oxidation of 40 g of nickel in the proportions:
58,7: 98 = 40: X; X = (98 . 40) / 58.7 = 66.78 rub.
Vіdpovid: 133.56 g; RUB 66.78 However, the oxidation of nickel consumes a lot of sulfuric acid.
Vikladach: Korablyova A.A.
ZVIT
About the laboratory robot
COURSE: ZAGALNA CHEMISTRY
"STRONG REACTIONS IN ROZCHINS"
OF 62 5528 1.04 LR
Robotu Vikonav
student groupie
Saint Petersburg
Meta robots:
Calculate the liquidity constant, temperature coefficient, activation energy of the reaction between sodium thiosulfate and sulfuric acid.
This laboratory robot tests the reaction between sodium thiosulfate (hyposulfite) Na2S2O3 and sulfuric acid H2SO4.
This reaction occurs in two stages:
1) (shvidko)
The first stage of ion exchange proceeds until mid-stage. Thiosulfuric acid is an unstable semi-solid that disintegrates into a white precipitate.
2) (full)
The fluidity of the reaction can be judged by the appearance of opalescence and the subsequent cloudiness of the liquid that has fallen.
The overall reaction is indicated by another stage of the process, which is based on the concentration of H2SO4, and also Na2S2O3 (pseudo-molecular reaction).
Kinetic jealousy looks like:
Adjust and react:
Thermostats, thermometers, measuring cylinders, test tubes, test tube trimmers, stopwatches, Na2S2O3 and H2SO4 units.
Evidence No. 1:
Add thiosulfate to the liquidity of the chemical reaction.
Dependency of the fluidity reaction of the concentration of sodium thiosulfate.
Processing of the results in detail:
We can determine the speed of the reaction using the formula:
2. Coming from the kinetic equation, the values of the reaction fluidity constant are determined:
R 
3. The average value of the constant for a given room temperature is significant, when T = 14 degrees Celsius.
4
. Vary the degree of fluidity of the reaction depending on the concentration of thiosulfate – graphically. (Div. Fig. No. 1).
5. Graphically calculate the velocity constant of the reaction as the tangent of the slope of the straight line OA to the abscissa axis. The constant is graphically equal to its analytical values.
KMR = tg = 0.162 KSR = 0.17 KMR KSR
Evidence No. 2:
Increase the temperature to determine the fluidity of the chemical reaction.
|
Temperature before the day T, deg Celsius. |
reaction t, s |
Bring in. fluidity react. V, 1/s |
Const. shvidk. react. K, l/mol*s |
|
Processing of the results in detail:
1. Liquid liquid reaction at skin temperature:
The results can be seen in the following tables.
2. Based on the kinetic equation, the constant values for skin temperature are determined:
R 
The results can be seen in the following table.
3. The temperature influx on the fluidity of the chemical reaction is shown graphically. (Div. Fig. No. 2).
4. Based on the Van Hoff equation, the value of the temperature coefficient is calculated for the skin temperature range and the average value is calculated:
K2/K1 = 1 = 2.42
K3/K2 = 2 = 1.97 mid = 2.3
K4/K3 = 3 = 2.49
5
. Based on the Arrhenius equation, we calculate the analytical values of activation energy for the skin temperature range:
E 
a1 = 61785 J/mol Ea2 = 50729 J/mol Ea3 = 72882 J/mol
I calculate the average value:
EaAVED = 61798 J/mol
6. The graphical content of lgK in 1/T is determined by the calculated fluidity constants for different temperatures and the activation energy is calculated graphically (div. Fig. No. 3).
tg = - Еа / 2.3 R , then
EaGR = -2.3 R tan = -2.3 * 8.3 * tan = 19.09* 3230 = 61660 J/mol
7. The equal value of the activation energy of the graphical and analytical way:
EaGR = 61660 J/mol EaGRED = 61798 J/mol EaGR EaGR
Visnovok:
At a temperature above const, the speed of the chemical reaction is proportional to the concentration of the substances that take part in this reaction. (Div. Fig. No. 1)
With increased temperatures, the fluidity of the chemical reaction increases
For the reason that the concentration becomes unchanged. It can be explained that as the temperature increases, atoms and speech go to greater awakenings, so that they remove additional energy - the activation energy necessary for the breakdown of the chemical bond and the creation of a new speech.
Sodium thiosulfate is a synthetic substance, known in chemistry as sodium hydroxide, and in the food industry as an additive E539, which is allowed until it is used in the production of food products.
Sodium thiosulfate functions as an acidity regulator (antioxidant), anti-steel agent or preservative. The addition of thiosulfate as a grub additive allows you to increase the preservation and viscosity of products, prevent rotting, souring, and fermentation. In pure form, this product plays a role in the technological processes of preparing grub iodized salt as an iodine stabilizer and is used for processing baker's beard, which is soft to the point of compaction.
The production of grub additive E539 is limited exclusively to the industrial sector, and is not available in retail sales. For medical purposes, sodium thiosulfate is used as an anti-tear for severe illnesses and as an anti-inflammatory remedy for external congestion.
private news
Thiosulfate (hyposulfite) is an inorganic compound that is the sodium sulphate of thiosulfuric acid. Rechovina is a barless, odorless powder that, upon closer inspection, appears as clear monoclinic crystals.
Hyposulfite is an unstable semi-solid that does not form in nature. Rechovina creates a crystalline hydrate, which, when heated to 40 °C, melts in wet crystalline water and disintegrates. Sodium thiosulfate melts quickly before supercooling, and at temperatures around 220 ° the unit will collapse.
Sodium thiosulfate: synthesis
Sodium acidic acid is the first to be removed by piecemeal in laboratory minds using the Leblanc method. This mixture is a by-product of soda synthesis, which is created after the oxidation of calcium sulfide. Reacting with acid, calcium sulfide is often oxidized to thiosulfate, which, along with sodium sulfate, contains Na 2 S 2 O 3.
Modern chemistry offers a number of methods for the synthesis of sodium sulfuric acid:
- oxidation of sulfides with sodium;
- boiling syrup with sodium sulfite;
- interaction between sulfur water and sulfur oxide with sodium hydroxide;
- boiling syrup with sodium hydroxide.
These methods allow you to isolate sodium thiosulfate as a by-product of the reaction or in the form of aqueous solution, which requires evaporation of the liquid. It is possible to remove the excess of sodium sulfate by removing its sulfide from acid-saturated water.
Pure anhydrous thiosulfate is the result of the interaction of sodium salt and nitrous acid with sulphur in a solution known as formamide. The synthesis reaction takes place at a temperature of 80 °C and is released near the surface and its products – thiosulfate and thiol oxide.
In all chemical reactions, hyposulfite acts as a strong catalyst. In reactions involving strong oxidizing agents, Na 2 S 2 O 3 is oxidized to sulfate or sulfuric acid, and weak ones to tetrathione salt. The oxidation reaction to thiosulfate is the basis of the iodometric determination method.
Thankfully, the interaction between sodium thiosulfate and strong chlorine, which is highly oxidizing and potent, is due. Hyposulfite is easily oxidized by chlorine and converts it into water-soluble compounds. In this way, it half-crosses the ruinous and toxic influx of chlorine.
In industrial mines, thiosulfate is obtained from gas production outlets. The most abundant substance is lamp gas, which is found during the coking process of coal and dissolves in hot water. From this, calcium sulfide is synthesized, which is subjected to hydrolysis and oxidation, and then combined with sodium sulfate to remove thiosulfate. Regardless of the high-stage nature, this method is the most economical and environmentally friendly method in the form of hyposulfite.
| Systematic hiring | Sodium thiosulfate |
|---|---|
| Traditional names | Sodium acid oxide, sodium hyposulfite, antichlorine |
| International marking | E539 |
| Chemical formula | Na2S2O3 |
| Group | Inorganic thiosulfates (salts) |
| Aggregate mill | Bare-free monoclinic crystals (powder) |
| Rozchinnist | Rozchinniy, non-rozchinniy |
| Melting temperature | 50 °C |
| Temperature is critical | 220 °C |
| Powerful | Antioxidative, complexing |
| Category of grub additives | Acidity regulators, anti-stitch agents (anti-stitch agents) |
| Pokhodzhennya | More synthetic |
| Toxicity | Chi is not understood, the speech is mentally careless |
| Regions of stagnation | Kharchova, textile, textile industry, photo reference, pharmaceuticals, analytical chemistry |
Sodium thiosulfate: stagnation
Sodium hydroxide was used for various purposes long before it was added to the warehouse for grub additives and medicines. Gauze bandages and filters of gas masks were leaked with antichlorine to protect respiratory organs from chlorine cleaning during the First World War.
Current directions for stagnation of hyposulfite in industry:
- Processing of photographic melting and fixing is depicted on a photo paper;
- dechlorination and bacteriological analysis of drinking water;
- removal of chlorine stains when washing fabrics;
- mining of gold ore;
- production of copper alloys and patina;
- tanned hide.
Sodium oxyhydroxide is used as a reagent in analytical and organic chemistry, it neutralizes strong acids, removes important metals and their toxic substances. Reactions between thiosulfate and various substances are the basis of iodometry and bromometriya.
Kharchova additive E539
Sodium thiosulfate is not a widely used grub additive and is not readily available due to the instability of the product and the toxicity of the products and its breakdown. Hyposulfite is used in technological processes for the production of grub iodized salt and bakery herbs as an acidity regulator and anti-stitch agent (anti-caking agent).
Additive E539 functions as an antioxidant and preservative in the preparation of canned vegetables and fish, desserts and alcoholic beverages. This mixture also enters the storage of chemicals that are applied to the surface of fresh, dried and frozen vegetables and fruits.
Preservative and antioxidant E539 are used to enhance the viscosity of such products:
- fresh and frozen vegetables, fruits, seafood;
- , peas, nasnya;
- vegetables, mushrooms and vegetables, canned or oils;
- jam, jelly, canned fruit, fruit puree and fillings;
- fresh, frozen, smoked and dried fish, seafood, canned food;
- boron, starch, sauces, seasonings, otset;
- white and round, sugar substitutes (dextrose and), sugar syrups;
- fruit and vegetable juices, licorice, water, low-alcohol drinks, grapes.
When preparing kitchen iodized salt, the grub additive E539 is stagnated to stabilize the iodine, which allows the product to properly last and preserve its grub value. The maximum permissible concentration of E539 in kitchen salt is 250 mg per 1 kg.
In bakery products, sodium thiosulfate is actively used in the warehouse of various product additives. Bakery coloring agents can be oxidative and destructive. Antistezhuvach E539 is brought to the polypshuvach action, which renews how it is possible to change the government.
The dough is made from a fine grain with gluten, it tends to tear quickly, is poorly processed, sits, does not reach the necessary temperature and cracks during the kneading process. Anti-caking agent E539 combines disulfide bonds and the structure of gluten proteins, as a result of which the dough rises well, the flesh becomes fluffy and elastic, and the crust does not crack when kneaded.
At productions, the anti-skid agent is added quickly with yeast just before mixing the dough. Instead of thiosulfate in the mucus, it is necessary to add 0.001-0.002% of its mass according to the technology for the preparation of baked goods. The sanitary and hygienic standards for the E539 additive are 50 mg per 1 kg of wheat borochon.
Antistezhuvac E539 is used in technological processes at strict dosing, therefore the risk is caused by thiosulfate during the incorporation of borgot germs on a daily basis. Boroshno, intended for individual sales, not pre-purchased before sale. Within normal limits, the supplement is safe and does not cause toxic effects on the body.
Vikoristannya in medicine and its impact on the body
Soda hyposulfite is included in the World Health Organization as one of the most effective and safe medicinal preparations before the transfer of essential medicinal products. It should be administered under the skin, internally and internally as a means of injection or as an external remedy.
Since the beginning of the 20th century, sodium thiosulfate has been the first to be used as a counteract when removed with hydrocyanic acid. In combination with sodium nitrite, thiosulfate is recommended for especially severe attacks of cyanides and is administered internally to convert the cyanides into non-toxic thiocyanates, which can then be safely removed from the body zmu.
Medical treatment of sodium sulfuric acid:
The infusion of hyposulfite into the human body through oral administration has not been confirmed, so it is impossible to judge the measles and harm of speech from a pure appearance or from the storage of food products. The release of the additive E539 has not been registered, so it is considered non-toxic.
Sodium thiosulfate and legislation
Sodium thiosulfate is added before the transfer of grub additives, which are allowed for curing when preparing grub products in Russia and Ukraine. Anti-steel agent and acidity regulator E539 are used in accordance with established sanitary and hygienic standards, including industrial methods.
Considering that the effect of the chemical substance on the human body when administered orally is not confirmed, the E539 additive is not allowed for administration in the EU and USA.
Meta-activity: experimentally determined factors that influence the speed of a chemical reaction (catalysts, surface area) and chemical reactivity.
Activity plan:
Materials and equipment: a stand with test tubes, a glass stick, diet, water, powder: aluminum, iodine, potassium chloride, ingredients: salt (III) chloride, potassium thiocyanate, potassium chloride.
Laboratory workshop
Step 1. Pour in the catalyst to determine the speed of the chemical reaction.
Using a spatula, add a small amount of aluminum powder and finely ground iodine to a dry test tube. Instead of the test tube, mix with a glass stick and add a drop of water. How does water flow into the fluidity of the reaction? On the stage of research 1-3, make tests on the concentration, temperature and catalyst flow for the fluidity of chemical reactions.
Evidence 2. Reduction of chemical reactivity when changing the concentration of reacting compounds.
Pour approximately 1 ml of 0.0025 M chloride (III) into the test tube and add the same 0.0025 M potassium thiocyanate. How does the farm industry change? Remove the ingredients and pour equal amounts into the test tubes. Discard one test tube as a control. Add to another test tube a handful of droplets of rose-saturated chloride (III), to the third - a handful of droplets of rose-saturated potassium thiocyanate, to the fourth - a handful of crystals of potassium chloride. Equalize the preparation of materials in test tubes. The slopes of the reverse reaction. Write a mathematical expression for the constant of chemical flux in this process. What kind of words are there in the process of chemical flux? How does rechovina give the price of red barley? How does the intensity of the preparation of the solution change when salt(III) chloride, potassium thiocyanate, and potassium chloride are added? Who directly has the same tracking system in theirs? What concentrations should be changed in order to move the chemical concentration to the right? Livoruch?
Food and food
1. What is the reason for the change in the speed of the reaction when the catalyst is introduced?
2. What reactions are called negative reactions? How is the chemical flow characterized? What is called the constant of equity, which officials should lie down?
3. What external influxes can destroy the chemical flow? Who is directly responsible for changes in temperature? Vice?
Laboratory robot № 11
Topic: Basic patterns of chemical reactions.
Meta-activity: Discard and follow the power of the most widespread simple speeches and spoluk.
Activity plan:
1. Repeat the basic nutritional chemical kinetics.
2. Conduct a laboratory experiment behind the premises of the vikladach.
Adjust the dishes: 1) The anniversary date with a second hand or a stopwatch. 2) The inner cylinder has a capacity. 20 ml.3) Thermometer at 100 °. 4) The tube is sealed with nitrogen dioxide 5) The tripod is sealed with a ring. 6) Palnik. 7) Chemical flasks capacity. 200 ml 2 pcs. 8) The mesh is asbestos. 9) A stand with test tubes.
Reagent: potassium chloride KS1.
Rozchini: 1) Syrchanic acid H 2 S0 4 (1:200). - 2) Sodium acid oxide Na2S20 3 (W n 1:200).
Laboratory workshop
Dosvid 1.
The degree of fluidity of the reaction depending on the concentration of the reacting substances
a) Add a little H 2 SO 4 until Na 2 S 2 0 3 is mixed. Beware of the coming turbid discord. The cloudy color is caused by the interaction of hyposulfite and sulfuric acid, which results in a cloudy sulfur. The reaction follows the ranks
Na 2 S 2 0 3 + H 2 S0 4 = Na 2 S0 4 + SO 2 + H 3 0 + S
The hour that passes from the beginning of the reaction to the visible cloudiness lies in the fluidity of the reaction.
b) Three large test tubes filled with dilutions (1:200)
Rozchin Na 2 S 2 O 3 in a pershu - 5 ml, in a friend - 10 ml,
for a third - 15 ml. Instead of the first test tube, add 10 ml of water and the other - 5 ml of water.
Pour 5 ml of diluted (1:200) sulfuric acid into three other test tubes.
Add 5 ml of H 2 S04 to the skin test tube with Na 2 S 2 0s while stirring and accurately mark the second hand of the year, how many seconds after adding the acid to prevent the formation of calamut in the skin test tube.
Formulate a statement about the degree of fluidity of the reaction based on the concentration of the reacting compounds in this data.
Dosvid 2 Degree of fluidity reaction depending on temperature
For further investigation, take Na 2 S 2 0 3 and H 2 S0 4 at the same concentration as before.
Pour 10 ml of hyposulfite into three large test tubes, 10 ml of sulfuric acid into the other three test tubes and divide them into three pairs: a test tube with Na 2 S 2 0 3 and a test with H 2 S0 4 in the skin pair.
Determine the temperature in the laboratory at the same hour by the second hand of the indicator, separate the first pair of test tubes at once and determine after how many seconds the calamut appears.
Place another pair of test tubes in a chemical flask with water and heat to a temperature of 10° higher per room. Monitor the temperature with a thermometer and lower it into the water. Pour into the test tubes and determine in how many seconds the kalamut will appear.
Repeat with the third pair of test tubes, heating them in a flask with water to a temperature of 20° higher per room.
Write down the results using the offensive form:
The slope of the graph illustrates the extent of the fluidity reaction depending on the temperature of the given data. To do this, plot the temperature of the traces on the abscis axis, and on the ordinate axis the values turned to the hour of the appearance of calamuti (one, divided by the number of seconds).
Laboratory robot No. 8
Subject: Rozchini. Preparation of components by percentage concentration
Purpose of the activity: to prepare foodstuffs with a given percentage concentration.
Activity plan:
1. Repeat the basic nutritional chemical kinetics.
2. Conduct a laboratory experiment behind the premises of the vikladach.
Laboratory workshop
Dosvid1. Prepare 10% sodium chloride in a mass of 50 g.
Calculate how much sodium chloride you need to prepare 10% for the amount of 50 rubles. Add this mass of salt to the previously mentioned mixture using technical chemical means with an accuracy of up to 0.01 r. Unrahuvat, which is the obligation of water necessary to dismantle the taken hanging. Use a beaker to measure the volume of water and dissolve the remaining salt. Remove the particles, enter the cylinder and measure the thickness of the mixture in the hydrometer, and then the mass fraction of sodium chloride. Calculate the kidnapping before the fact
Control nutrition and management.
1. What is it? What is called a robber?
2. How can you speed up the dismantling process? What kind of boxes are responsible for dismantling?
3. What is crystallized and crystallized water? How does the storage of solids depend on temperature? How does the intensity of gases change due to changes in temperature and pressure?
4. What is called concentration of business? What types are called molar, normal?
Laboratory robot No. 9
Subject: Preparation of different molar and normal concentrations.
Meta-activity: prepare ingredients of a given molar and normal concentration.
Activity plan:
1. Repeat the basic nutritional chemical kinetics.
2. Conduct a laboratory experiment behind the premises of the vikladach.
Materials and equipment: hydrometer set, 500 ml cylinder, sodium chloride, barium chloride crystal hydrate, solutions: sulfuric acid, hydrochloric acid.
Laboratory workshop