What Is the Connection Between Ethanol and Sulfuric Acid?

Colorless or white crystals, granules or powder, also known as alum. No smell. Astringent. Weathered in dry air, all crystal water is lost at 280 ° C and decomposed above 500 ° C. 1g is soluble in 0.6ml of water and 2.5ml of glycerin, but insoluble in ethanol. The aqueous solution is acidic to litmus and has a pH of about 4.5. Containing 1 molecule of crystal water is less likely to agglomerate. The relative density is 1.97. 100 ° C melting point. The minimum lethal dose (rat, oral) is 2200mg / kg. Irritating. Used in the manufacture of Lide powder, and used as mordant, astringent, wood preservative, etc.

Zinc sulfate (white vitriol), also known as alum or zinc alum, is colorless or white orthorhombic crystal or powder at room temperature, has astringency, is easily soluble in water, and the aqueous solution is acidic. . Pure zinc sulfate does not turn yellow when stored in the air for a long time, and loses water in dry air to become a white powder. There are many hydrates: the stable hydrate that is in equilibrium with the water phase in the range of 0-39 ° C is zinc sulfate heptahydrate, zinc sulfate 6-hydrate in 39-60 ° C, and zinc sulfate monohydrate in 60-100 ° C. When heated to 280 ° C, various hydrates completely lose crystal water, decomposed into zinc oxide sulfate at 680 ° C, further decomposed above 750 ° C, and finally decomposed into zinc oxide and sulfur trioxide at about 930 ° C. ZnSO4 · 7H2O and MSO4 · 7H2O (M = Mg, Fe, Mn, Co, Ni) form mixed crystals within a certain range. It is mainly used as raw material for the production of pigment Lide powder, zinc barium white and other zinc compounds. It is also used as a nutrient for animal lack of zinc, a feed additive for animal husbandry, zinc fertilizer (microelement fertilizer) for crops, and important for artificial fiber Materials, electrolytes for electrolytic production of zinc metal, mordants in the textile industry, medical emetics, astringents, fungicides, wood and leather preservatives, etc. It is obtained by the action of zinc or zinc oxide and sulfuric acid or by extraction and refining of sphalerite in a reflection furnace.

Physical properties

CAS number

EINECS No. 231-793-3

Appearance and properties: Colorless orthorhombic crystal, granules or powder, odorless and astringent.

Melting point (° C): 100

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Health hazards: The product is moderately irritating to the eyes and non-irritating to the skin. Ingestion can cause symptoms of acute gastrointestinal inflammation such as nausea, vomiting, abdominal pain, diarrhea, dehydration, shock in severe cases, and even death.

Environmental hazards: Harmful to the environment and can cause pollution to water bodies.

Explosion hazard: The product is non-combustible and irritating. ^[1]

Skin contact: Remove contaminated clothing and rinse with running water.

Eye contact: Raise eyelids and rinse with running water or saline. Seek medical attention.

Inhalation: Quickly leave the scene to fresh air. Keep your airways open. If breathing is difficult, give oxygen. If breathing stops, give artificial respiration immediately. Seek medical attention.

Ingestion: Rinse mouth with water and drink milk or egg white. Seek medical attention. ^[1]

Operation: Closed operation, local exhaust. Prevent dust from being released into the workshop air. Operators must be specially trained and strictly abide by the operating procedures. It is recommended that operators wear self-priming filter dust masks, chemical safety protective glasses, rubber acid and alkali resistant clothing, and rubber acid and alkali resistant gloves. Avoid generating dust. Avoid contact with oxidants. Equipped

Add ammonium chloride and potassium iodide to the zinc sulfate solution to eliminate the interference of iron and other impurities. Titrate with xylenol orange as the indicator at a pH value of about 5.5 and disodium ethylenediamine tetraacetate standard solution.

The detailed steps are as follows:

Method name: Zinc sulfate-Determination of zinc sulfate-complexometric titration.

Application range: This method uses complex titration to determine the content of zinc sulfate (ZnSO ₄ · 7H ₂ O).

This method is suitable for the determination of zinc sulfate.

Principle of the method: Take an appropriate amount of the test product, dissolve it in water, use chrome black T as an indicator, and titrate with ethylenediamine tetraacetic acid sodium titration solution (0.05mol / L) until the solution changes from purple to pure blue. Each 1mL of ethylenediamine tetraacetic acid sodium titration solution (0.05mol / L) is equivalent to 14.38mg of ZnSO ₄ · 7H ₂ O, and calculated.

Reagent: 1. Water (new boiling to room temperature)

2. Disodium ethylenediamine tetraacetate titration solution (0.05mol / L)

3. Reference zinc oxide

4. Dilute hydrochloric acid

5. Methyl red in ethanol solution (0.025%)

6. Ammonia test solution

7. Chrome black T indicator

8. Ammonia-ammonium chloride buffer (pH 10.0)

equipment:

Sample preparation: 1. Disodium ethylenediamine tetraacetate titration solution (0.05mol / L)

Preparation: Take 19 g of disodium ethylenediamine tetraacetate, add freshly boiled cold water to 1000 mL, and shake well.

Calibration: Take 0.12g of reference zinc oxide which is burned to constant weight at 800 , accurately weigh, add 3mL of dilute hydrochloric acid to dissolve, add 25mL of water, add 1 drop of 0.025% methyl red ethanol solution, and dropwise add ammonia test solution to The solution is yellowish, add 25mL of water and 10mL of ammonia-ammonium chloride buffer (pH10.0), add a small amount of chrome black T indicator, titrate with this solution until the solution changes from purple to pure blue, and use the titration result with Blank test correction. Each 1mL of ethylenediaminetetraacetic acid disodium titration (0.05mol / L) is equivalent to 4.069mg of zinc oxide. Calculate the concentration of the solution based on the consumption of the solution and the amount of zinc oxide taken.

Storage: Keep in glass stopper bottle, avoid contact with rubber stopper, rubber tube, etc.

Dilute hydrochloric acid

Take 234mL of hydrochloric acid and dilute to 1000mL with water to obtain. This solution should contain HCl at 9.5-10.5%.

3. Ammonia test solution

Take 400mL of concentrated ammonia solution and add water to make it into 1000mL.

4. Chrome black T indicator

Take 0.1 g of chrome black T, add 10 g of sodium chloride, and grind evenly to obtain.

5. Ammonia-ammonium chloride buffer (pH 10.0)

Take 5.4g of ammonium chloride, add 20mL of water to dissolve, add 35mL of concentrated ammonia solution, and then add water to dilute to 100mL.

Operation steps: Take about 0.3g of this product, weigh it accurately, add 30mL of water to dissolve, add 10mL of ammonia-ammonium chloride buffer (pH10.0) and a little chrome black T indicator.

Note 1: "Precise weighing" means that the weighed weight should be accurate to one thousandth of the weighed weight. "Precision weighing" means that the accuracy of the measured volume should meet the accuracy of the pipette in the national standard Claim.

Note 2: "Determination of moisture" uses the drying method, taking 2 to 5 g of the test sample, and spreading it in a flat weighing bottle that is dry to constant weight, the thickness does not exceed 5 mm, and the loose test sample does not exceed 10 mm. Open the bottle cap and dry at 100 ~ 105 ° C for 5 hours. Place the cap on the dryer, cool it for 30 minutes, and weigh it precisely. Then dry it at the above temperature for 1 hour, cool, and weigh until two times in a row. The difference in weighing does not exceed 5 mg. Calculate the moisture content (%) in the test product based on the weight lost. ^[5]