On the question of putting anhydrous copper sulphate in a copper sulphate solution

I have had such thoughts before, on this issue, you only considered one aspect, first of all, copper sulfate crystallization requires very little water, and the solubility of copper sulfate is relatively large, it will not have much impact on copper sulfate, if you think the same, then the whole solution will become bile alum.

Another thing that you don't take into account is that there is a dynamic equilibrium inside the container at this time, and there are both solutions converted into crystals and crystals converted into solutions, which is something you will learn later so that the explanation is easy to understand.

Then I'll give you a similar question.

Air can be dissolved in water, the water temperature increases, the solubility of the air will decrease, if I boil the water, then after a long time, will the boiling water still bubble?

The solubility of copper sulfate is 25g, which is equivalent to the solubility of copper sulfate pentahydrate is 25*250 160=39(That's the key, it's half the way to think about it).

Anhydrous copper sulfate powder can precipitate copper sulfate pentahydrate.

Water is consumed, and this water is soluble.

Therefore, the common rationale can solve the problem of other hydrates.

Or a normal algorithm.

The solution is still a saturated solution after the precipitated crystal, and the mass fraction of the solute does not change the equation.

Let the mass of CuSO4 in the original 100g saturated solution be x, and let the precipitated mass be y25g (100g+25g)=x 100gx=20g(20g+y=).

Thinking too much. I think it's okay not to react.

Anhydrous copper sulfate precautions

1. Hydrogen peroxide.

It should be added slowly in divided drops.

2. When filtering while hot, the filter device should be cleaned and preheated first; Prepare the filter paper and re-wet it when it is filtered.

3. Heat and concentrate in a water bath until there is a crystal film on the surface, and the solution cannot be evaporated.

4. The concentrate is naturally cooled to room temperature.

5. Recrystallization.

, adjust the pH to 1 2, and the amount of water added should not be too much.

6. ** Products and mother liquor.

Pretreatment of scrap copper chips.

1. Weigh g copper scraps and put them in a 150 ml Erlenmeyer flask.

10 ml of 10% Na2CO3 solution was added, heated and boiled to remove the surface oil, the lye was removed by decanting, and washed with water.

2. Simple process: Add 10 ml of 6 mol L H2SO4 solution, slowly add 30% H2O2 3 4 ml dropwise, heat in a water bath (the reaction temperature is kept at 40 50), after the reaction is complete (if there is excess copper chips, add dilute H2SO4 and H2O2), heat and boil for 2 minutes, and filter while hot.

Transfer the solution to an evaporation dish.

Adjust pH1 2 in a water bath and heat and concentrate until there is a crystal film on the surface, remove the evaporation dish, cool to room temperature, and filter to obtain mu-type copper of sulfuric acid pentahydrate.

Crude product Dry or blot Weigh Calculate yield.

Anhydrous copper sulfate was purified by recrystallization method.

Crude product water = 1 mass ratio), add a small amount of dilute H2SO4, adjust pH to 1 2, heat to dissolve all of them, and filter while hot (if there are no insoluble impurities, it can not be filtered).

The filtrate is naturally cooled to room temperature (if there is no crystal precipitation, the water bath is heated and concentrated until a crystal film appears on the surface), and a small amount of absolute ethanol is used.

Washing products, suction filtration. Transfer the product to a clean surface dish, blot it with absorbent paper, weigh it, and calculate the yield.

Copper sulphate plus water is not necessarily a copper sulphate solution.

Copper sulphate with water:

1) A small amount of water generates copper sulfate crystals (CuSO4·5H2O) CuSO4+5H2O=CuSO4·5H2O(2) If there is more water, it will become a solution.

Copper sulphate is sealed and stored.

Anhydrous copper sulphate is a white powder that is sensitive to water only and absorbs water in the air, so it is enough to prevent contact with water (water vapor).

The preservation method is to store it sealed.

If the color of the powder is found to be blue, it means that it has absorbed water, but it can be heated at 300 degrees Celsius, and after dehydration, anhydrous copper sulfate powder can be re-obtained, which is simple to operate, so there is no need to spend too much effort on preservation.

1. Copper sulfate pentahydrate is a pure substance, commonly known as bile alum. It is copper sulfate with 5 crystalline water, and it is blue crystal at room temperature. Copper sulphate solution is a solution formed by dissolving copper sulphate in water, which is blue.

Pure copper sulphate without crystallized water is a white powder. We add water dropwise to copper sulfate to get copper sulfate pentahydrate, because copper sulfate can "pull" five water molecules to bind. When the amount of copper sulphate and the amount of water reach 1:

At 5 o'clock, the copper sulfate will all become copper sulfate pentahydrate, at this time can no longer absorb water, if you continue to add water dropwise, it will form a copper sulfate solution. Due to the water absorption of copper sulfate, copper sulfate is often used as a desiccant, because the color of pure copper sulfate turns blue after encountering water, and it is often used to test the existence of water.

2. Use glass bottles to store them, and add a small amount of sulfuric acid to prevent copper ion hydrolysis.

Copper sulfate is dissolved in water to form a copper sulfate solution. Copper sulfate solution (CuSO4) is a sky blue solution, which is weakly acidic, commonly known as bile alum, stone bile, bile alum, and blue alum. Copper sulphate is an important raw material for the preparation of other copper compounds.

Bordeaux liquid can be obtained by mixing with lime milk, which is used as a fungicide. Copper sulphate is also the electrolyte used in electrolytic refining of copper.

Copper sulfate (cupricsulfate), an inorganic compound, chemical formula CuSO4. It is white or off-white powder. The aqueous solution is weakly acidic and appears blue.

However, when Ranzhao crystallizes from the aqueous solution, it produces blue copper sulfate pentahydrate (Cuso4·5H2O, also known as bile alum), which can be used to test the presence of water. After losing the crystalline water ridge after being heated, it decomposes, and is very stable at room temperature and pressure, does not deliquescent, and will gradually weathered in dry air.

Copper sulfur source socks is soluble in water. The aqueous solution is weakly acidic and appears blue. However, when crystallized from an aqueous solution, blue copper sulfate pentahydrate (CuSO4·5H2O, also known as bile alum) is generated, and this principle can be used to test the presence of water.

It decomposes after losing crystal water after being heated, and is very stable at room temperature and pressure, without deliquescent, and will gradually weathered in dry air.

Copper sulfate solution (CuSO4) is a sky blue solution, which is weakly acidic, commonly known as bile alum, stone gall, bile alum, and blue alum. Copper sulphate is an important raw material for the preparation of other copper compounds. Bordeaux liquid can be obtained by mixing with lime milk, which is used as a fungicide.

Copper sulphate is also the electrolyte for electrolytic refining of copper when it starts cracking and rolling.

Copper sulfate is easily soluble in water, and sulfuric acid should be added when dissolved because of the blue color of hydrated copper ions, so anhydrous copper sulfate is often used to test the presence of water in the laboratory. In real production and life, copper sulfate is often used to refine copper, and mixed with hydrated lime to make pesticide Bordeaux liquid.

Copper sulphate can be used to kill fungi. Most fungi can be killed with very low concentrations of copper sulfate. It is reasonable to add an appropriate amount of copper sulfate to the swimming pool and will not cause much harm to the human body.

The national standard stipulates that copper sulfate in swimming pools is, within this range, copper sulfate is safe for the human body. If copper sulfate is used, the maximum dosage should not exceed 1 milliliter.

Heat to concentrate, cool crystallization.

1. Principle: The solubility of the saturated solution of copper sulfate increases significantly with the increase of temperature, and the method of preparing crystals is often made with a cooled hot concentrated solution (the saturated solution has a better effect).

2. Supplies: beakers, surface dishes, iron frames, alcohol lamps, asbestos nets, funnels, measuring cylinders, glass rods, tweezers, filter paper, fine wires, copper sulfate crystals (CuSO4·5H2O).

3. Operation:

1. Preparation of small crystals: In a beaker containing 100ml of water, add 10g of finely ground copper sulfate powder, and add 1ml of dilute sulfuric acid (to prevent copper sulfate hydrolysis), and heat to completely dissolve the crystals. Continue to heat to 80-90, filter while hot, and the filtrate flows into a beaker that has been washed and warmed with hot water, and the lid is allowed to stand.

After a few hours or overnight, you will notice the formation of several small crystals at the bottom of the cup.

2. The growth of small crystals: pick a crystal with a relatively complete crystal shape, tie it with a thin wire, hang it in a beaker containing saturated copper sulfate solution, and cover it to stand. Add a small amount of slightly hot saturated copper sulfate solution to the beaker every day, and the small crystal will gradually grow into a large crystal.

The key to success or failure: 1) The reagent used must be pure, and it is difficult to obtain a complete crystal form if it contains impurities.

2) Control the concentration of the solution, if the solution is too concentrated, the crystallization rate is too fast, and it is not easy to form crystals with complete crystal shape; If the concentration of the saturated solution is not large, the crystallization rate is too slow, and the small crystals grow slowly. When preparing small crystals, use a saturated solution 20 -30 above room temperature; The saturated solution added later should be a solution higher than room temperature 15 -20, the amount of each addition is about 1 10 of the original solution, the crystals should be taken out when added, and the crystals should be immersed after the temperature of the solution is uniform.

3) Pay attention to the change of ambient temperature, the saturated solution should be cooled slowly, and the beaker can be wrapped with cloth or cotton. The crystals can be removed during the day when the temperature is high and put back into the solution at night.

4) The container used must be clean and covered to prevent dust from falling in.

3. Preparation of small crystals: If the crystals precipitated by a crystallization are too small, a few crystals with intact crystals can be picked up and cultured with a saturated solution higher than room temperature to make them grow enough to be tied with a fine wire. You can also hang a fine line in the filtrate, and when the solution cools, small crystals will be precipitated on the fine line, and one crystal shape will be kept intact (the rest will be peeled off) to make the crystal seed, and it will grow according to step 2.

4. Copper sulfate solution is easy to crystallize to form complete large crystals, and it is recommended to use the method of evaporation solvent to prepare large crystals.

Copper sulfate crystals can be obtained by heating the copper sulfate solution and cooling the solution.

Analysis: Add anhydrous copper sulfate, once the solution is supersaturated, copper sulfate crystals (copper sulfate pentahydrate) will be precipitated

Solids do not dissolve.

If CuSO4·5H2O is added, the solid and solution mass will generally remain unchanged, and the solid shape may change (due to dissolution equilibrium).

If anhydrous CuSO4 is added, the solid becomes blue and the solution decreases (anhydrous CuSO4 absorbs water and becomes a crystalline hydrate).

There is a precipitate, because it does not dissolve anymore.