Preparation of manganese sulfate solution, how to prepare a solution containing manganese sulfate wi

You weigh 100g of manganese sulfate first, and then add 1L of water.

The so-called supersaturation means that when you consume a part of the solute in a bottle of solution, this solution is still a saturated solution of the solute, for example, the solubility of NaCl in water is 36g, and you add 40GnaCl solid (100ml of water), then when you add a few drops of Agno3, the solute becomes a mixed solution of Na3 and NaCl, and NaCl is still saturated at this time, which is a property that saturated solutions do not have, so it is listed as a supersaturated solution.

- What is a supersaturated solution? - Know > Science & Engineering A supersaturated solution is a solution in which the amount of solute contained in the solution is greater than the amount of solute in the saturated solution at this temperature (i.e., beyond normal solubility). No solid solute must be present in the solution to produce a supersaturated solution.

To prepare a supersaturated solution, it is necessary to prepare a saturated solution at a higher temperature, and then slowly filter it to remove the excess unsoluble solute and slowly reduce the temperature of the solution to room temperature.

At this time, the concentration of the solution has exceeded the saturation value at room temperature and has reached a supersaturated state. The nature of a supersaturated solution (unstable), when a small solute crystal (as a "seed") is added to this solution, it can cause the crystallization of the solute in the supersaturated solution. The reason why supersaturated solutions can exist is because solutes do not easily form crystalline centers (i.e., crystal nuclei) in solution.

Because each crystal has a certain arrangement rule, there must be a crystal center, so that the solute particles that were originally moving in disorder can be gathered and arranged in the order unique to this crystal. Different substances have different degrees of difficulty in achieving this regular arrangement, and some crystals take a considerable amount of time to produce crystalline centers on their own, so the supersaturated solution of some substances still seems relatively stable.

But in general, the supersaturated solution is in an unbalanced state, is unstable, if it is vibrated or added to the solute crystal, the excess solute in the solution will precipitate and become a saturated solution, that is, converted into a stable state, which shows that the supersaturated solution is not as stable as the saturated solution, but there is still a certain stability. Therefore, this state is also called a mesostable state. - Preparation of ammonium ferrous sulfate-- know > Science and engineering > Chemistry Preparation of ammonium ferrous sulfate 1) Double salt:

a) Definition: A crystalline compound composed of two or more simple salts, such as: (NH4)2SO4·FeSO4·6H2O (molar salts).

b) Formation conditions: monovalent cations with large volume (such as K+, NH4+) and divalent cations with small radius (such as Fe2+, Fe3+, Al3+, etc.) are easy to form double salts. Thermodynamic perspective:

Lattice energy increases; Structure angle: small balls are installed in the gap of the large ball. c) Features:

a) the nature of the solution is indistinguishable from that of the mixed solution of the simple salts in which it is composed; (b) is more stable than the simple salts of the components that compose it; (c) The solubility is smaller than the simple salts that make up it.

The relative atomic mass of manganese.

is 55 and the molecular weight of manganese sulfate is 151.

Calculated as 1 L solution.

That is, milligrams of manganese sulfate are required.

Accurately weigh manganese sulfate solids, add an appropriate amount of water to dissolve thoroughly, and transfer to a milliliter volumetric flask.

Shabu wash beaker. The liquid continues to be transferred to a volumetric flask, diluted to the scale, and shaken well for later use.

Potassium permanganate solutionMethod of preparation:

Weigh the solid KMNO4 on a scale and place it in a 1000 ml beaker.

medium, add 500 ml of distilled water.

Heat and boil and cool), boil for about 1 hour, add a certain amount of distilled water in the middle, to keep the volume basically unchanged, and use a microporous glass funnel or glass wool after standing and cooling.

Funnel filtration, filtrate into a brown fine-mouthed bottle, labeling, one week later.

Calibrate and save for later use.

The KMno4 solution was calibrated with Na2C2O4 solution

Accurately weigh a copy of the reference substance Na2C2O4 and place it in a 250ml Erlenmeyer flask.

, add about 30ml of water to it to dissolve, then add 3mol·l-1H2SO415ml, cover the lid, heat to 75 85 (the temperature at the beginning of steaming) on the asbestos iron wire, take 25ml each time, three times in parallel, and titrate with potassium permanganate solution while hot.

The reaction speed is slow at the beginning of the titration, and after the mn2+ is produced in the solution, the titration speed can be appropriately accelerated until the solution is reddish and lasts for half a minute without fading. Titrate three times in parallel, and the KmNO4 concentration is calculated based on the mass of Na2C2O4 and the volume of the consumed KMnO4 solution. The other two Na2C2 O4 solutions were titrated in the same way, with relative mean difference.

should be within. PrecautionsDistilled water often contains a small amount of the original substance, which reduces KMno4 to Mno2·NH2O. Commercially available potassium permanganate contains fine powdered mNO2· NH2O can accelerate the decomposition of KMno4, so the KMno4 solution is usually boiled for a period of time, and after cooling, it needs to be placed for 2 3 days to make it fully functional, and then the precipitate is filtered and removed.

The aqueous solution of potassium permanganate releases oxygen slowly, and the soaking time must reach 5 minutes before it has the ability to sterilize for forest typePotassium permanganate solution can be used to wash wounds; It can also be used to disinfect tableware and tea utensils such as bowls and chopsticks, teacups, etc.

and fruits. When using potassium high manganese to disinfect fruits, tableware and other items, first soak the items to be disinfected in potassium permanganate solution for a few minutes, and then rinse them with water.

At room temperature, the reaction rate between KMno4 and C2O42- is slow, so heating increases the reaction rate. However, the temperature should not be too high, if the temperature exceeds 85, some H2C2O4 will decompose.

moles per liter (1 5 potassium permanganate).

c(kmno4)=

mol l is taken.

KMNO4 (mass), dissolve in a beaker and transfer to a 1 L volumetric flask.

The same goes for moles per liter (1 2 sodium oxalate).

n(c2h2o4)=

Same as above.

Preparation and calibration of KMNO4 solution.

1. Prepared KMNO4 solution 300ml

Weigh accurately. KMno4 is dissolved in 300ml of deionized water, boiled for 30 minutes, cooled and transferred to a dry brown reagent bottle, left for a week, filtered and set aside.

2. Calibration of KMno4 solution.

Na2C2O4 is commonly used for calibration of KMno4 solution, which is easy to purify and stable in nature. In a hot, acidic medium, KMno4 reacts with Na2C2O4 as follows:

2mno4-

5c2o42-

16h+=2mn2+

10co28h2o

The indicator during calibration is the KMno4 solution itself, and when the KMNO4 solution to be calibrated is titrated until the solution is pink, and the color does not fade within 30 seconds, it is the end point.

The chemical formula of manganese sulfate tetrahydrate is MnSO4 4H2O and its relative molecular mass is g mol. To prepare a solution of 5 mg l of manganese sulfate, the following calculation process can be followed:

Calculate the mass of manganese sulfate tetrahydrate contained in each liter of solution.

Each liter of solution contains 5 mg of manganese sulfate, then the mass of manganese sulfate tetrahydrate contained in 1 l of solution is:

5 mg/l × 1 l = 5 mg

Based on the relative molecular weight of manganese sulfate tetrahydrate, the molar mass of manganese sulfate tetrahydrate with a content of 5 mg was calculated.

The molar mass corresponding to 5 mg of manganese sulfate tetrahydrate is:

5 mg ÷ g/mol = mmol

Based on the molar mass of manganese sulfate tetrahydrate, the mass of manganese sulfate tetrahydrate with the content of mmol is calculated.

The quality of manganese sulfate tetrahydrate contained in manganese sulfate tetrahydrate of MMOL is:

mmol × g/mol = g

Therefore, to prepare 5 mg l of manganese sulfate solution, it is necessary to weigh the manganese sulfate compound of the old g.

Anode: 2mNO42-a2E- =2mNO4-

Cathode: 2h2o deca2e- =2oh-decah2

Total reaction: 2k2mNO4 + 2H2O = electrolysis = 2kmNO4 + 2koH + H2

Question 2: How to prepare 1:5000 potassium permanganate solution 1 gram of potassium permanganate, 5000 grams of water.

Prepare it in this ratio.

Similarly: 100 mg potassium permanganate, 500 g water.

10 mg potassium permanganate, 50 g water.

See how much you need.

Question 3: How to prepare 1% potassium permanganate solution? 1 gram of potassium permanganate dissolved in 1000 grams of water, approximately.

Usually used for disinfection, 1-5% dissolving liquid is prepared, which is not easy to measure accurately. You can put in the required amount of solution, first fill the container with water, then put in a very small amount, stir, until pink. It can be used for disinfection, foot soaking to cure athlete's foot, etc.

I also sometimes use it for disinfection when propagating plants by cuttings.

Question 4: What should be paid attention to in the preparation of potassium permanganate solution Precautions for the preparation of potassium permanganate solution:

The heating temperature should not be too high, if it exceeds 90, it is easy to cause decomposition

The color is darker, and the highest line along the liquid level should be used as the standard for reading;

Endpoint judgment: reddish for half a minute without fading is the end.