Where should NaOH be placed when weighing

In the small beaker, the beaker is too big to fit the scale, it should be a small beaker (am I a little too much).

Weighing usually uses a piece of paper, but if the weighing of sodium hydroxide is also used in the paper, the sodium hydroxide will be stained on the paper due to deliquescent, which will cause a large error (the paper will not turn black, because the sodium hydroxide is not dehydrated, and the upstairs is not mixed with concentrated sulfuric acid).

Also, weigh sodium hydroxide quickly to avoid large errors).

It is correct to weigh with a beaker. Your teacher should have had a demonstration experiment, that is, spraying a sodium hydroxide solution on paper, the paper will corrode and turn black. Due to the short time weighing, the deliquescent part does not need to be considered.

If it is a very accurate weighing, an electronic balance is used, which is a relatively complete sealing system with a desiccant in it, so it can prevent deliquescent. If a normal balance is used for weighing, it means that the weighing requirements have ignored the deliquescent part.

It is stipulated that it should be placed in glassware, and weighing with paper is not a standard way to save trouble. In fact, this weighing of sodium hydroxide will absorb water, but it is required to be fast during operation, so that the error will be reduced.

The weighing of NaOH should be placed in a beaker, mainly because of the corrosive nature of NaOH and the deliquescent factor is generally not considered.

NAOH does not react with glass.

Note that deliquescent is in storage, and it should be placed in a small beaker when weighing in the laboratory, and it will be configured into a solution after weighing, so there is no need to consider deliquescent.

Place in glassware.

NaOH generally reacts with glass only when it is in solution, and the inner wall of glassware is generally smooth, and it is not easy to react with general alkali.

In fact, when weighing, the laboratory conditions are required to be dry, but in fact, it is generally not considered because of the short weighing time.

Glassware (weighing flasks or small beakers).

It will take a long time to respond, so you just weigh it

<>First of all, sodium hydroxide needs to be weighed in a tray, and the correct operation method when weighing sodium hydroxide with a tray balance is: first put the sodium hydroxide in the beaker, and then weigh it with a tray, because the general drug is weighed on paper, and the drug that is easy to deliquescent or corrosive is weighed in a glassware, and the principle of left and right code should be followed, because sodium hydroxide is corrosive, so it should be weighed in a beaker, because the beaker is glass, and the glass belongs to sodium silicate and does not react with sodium hydroxide. Sodium hydroxide solids will corrode the paper on the paper, weighing sodium hydroxide can be in contact with air, deliquescent is very slow, as long as paper or other fiber products are not used.

(1) The amount of the prepared NaOH solution is 500ml, the amount of the substance that requires sodium hydroxide is: , and the mass of sodium hydroxide is 40g mol, so the answer is:

2) The instruments used to prepare the solution of a certain substance concentration are: tray balance, beaker, glass rod, medicine spoon, 500ml volumetric flask, rubber head dropper, etc., so when preparing, the instruments or supplies that must be used are: The instruments that are also needed are:

500ml volumetric flask, so the answer is: 500ml volumetric flask; (3) Sodium hydroxide is corrosive and easy to deliquescent, and must be weighed in a beaker, so it is correct, so it is selected; (4) The beaker and glass rod are not washed, resulting in a small amount of solute substances in the prepared solution and a low concentration of the solution, so it is wrong; The NaOH solution is transferred to the volumetric flask without cooling to room temperature, the volume of the hot solution is large, and the volume becomes smaller after cooling, resulting in the volume of the prepared solution being small, according to C=N V, the solution concentration is high, so it is correct; The volumetric flask is not dry, contains a small amount of distilled water, and the volume needs to be fixed later, and there is distilled water in the volumetric flask does not affect the preparation result, so it is wrong; The weighing time of NaOH is too long, resulting in the deliquescent of sodium hydroxide, partial deterioration, the amount of sodium hydroxide in the prepared solution is small, according to C=N V, the concentration of the solution is low, so it is wrong; Looking down at the scale when setting the volume, the volume of the distilled water added is small, and it can be seen that the concentration of the prepared solution is high according to c=n v, so it is correct; Therefore, it is chosen

Sodium hydroxide, with the chemical formula NaOH, commonly known as caustic soda, caustic soda, caustic soda, is a strong alkali with strong corrosiveness, generally in the form of flakes or granules, soluble in water (exothermic when dissolved in water) and forms an alkaline solution, and deliquescent, easy to absorb water vapor in the air (deliquescent), because it will absorb water vapor in the air, so the quality of sodium hydroxide will be large. Moreover, sodium hydroxide is highly corrosive, so it cannot be weighed on filter paper, and can only be weighed with a glass instrument. Therefore.

When preparing a solution of a certain substance concentration, sodium hydroxide should be weighed in a closed glass instrument.

Because sodium hydroxide is viscous and corrosive. If you use paper, it will stick to the paper. Moreover, it is very absorbent and continuously absorbs water from the air during weighing. Make the weighing inaccurate.

Sodium hydroxide, with the chemical formula NaOH, commonly known as caustic soda, caustic soda, caustic soda, is a strong alkali with strong corrosiveness, generally in the form of flakes or blocks, easily soluble in water (exothermic when dissolved in water) and forms an alkaline solution, and deliquescent, easy to absorb water vapor (deliquescent) and carbon dioxide (deterioration) in the air, hydrochloric acid can be added to test whether it is deteriorated.

NaOH is one of the essential chemicals in chemical laboratories and one of the common chemicals. Pure products are colorless and transparent crystals. Density.

Melting point. Boiling point 1390 . Industrial products contain small amounts of sodium chloride and sodium carbonate, which are white opaque crystals.

There are blocks, sheets, granules and rods, etc. Formula.

Sodium hydroxide can be used as an alkaline cleaning agent in water treatment, soluble in ethanol and glycerol; Insoluble in propanol, ether. It disproportionates with halogens such as chlorine, bromine, and iodine. It neutralizes with acids to form salt and water.

It will corrode the filter paper, so you can't use the filter paper, and you need something to pad it when you weigh the medicine....

NaOH is susceptible to water absorption and deliquescent in the air.

Sodium hydroxide is strongly corrosive and cannot be weighed on a piece of paper, and should be weighed in a beaker or other glassware; The use of tray balances should follow the principle of "left object and right code", so the tray balance should be used to weigh sodium hydroxide solids, and sodium hydroxide should be placed in the beaker on the left plate.

Sodium hydroxide, with the chemical formula NaOH, commonly known as caustic soda, caustic soda, caustic soda, is a strong alkali with strong corrosive terrestrial socks, generally in the form of flakes or granules, soluble in water (exothermic when dissolved in water) and forms an alkaline solution, and deliquescent, easy to absorb water vapor in the air. NaOH is one of the essential chemicals in chemical laboratories and one of the common chemicals.

After weighing the solid NaOH on a scale, the standard solution (e.g., potassium perhydrogen phthalate) needs to be calibrated to obtain its exact concentration.

Solid Naoh!, not on weighing paperBecause solid NaOH is highly corrosive and hygroscopic.

Sodium hydroxide is a white solid that dissolves easily in water and emits a large amount of heat. Solid sodium hydroxide exposed to the air easily absorbs moisture in the air, and the surface is moist and gradually dissolves, which is called deliquescent. Taking advantage of this property, sodium hydroxide can be used as a desiccant for certain gases (e.g., oxygen, hydrogen).

The result can only be accurate to 0,1g, and the error is large. For increased accuracy, an analytical balance can be used, which can be accurate.

Solid sodium hydroxide cannot be weighed with weighing paper, directly in a beaker. The reason is that sodium hydroxide is easily deliquescent and corrosive, which can corrode weighing paper and instruments.

Accurate, inaccurate, accurate naoh is easily deliquescent and easily left on the weighing paper.

Sodium hydroxide is strongly corrosive and cannot be weighed on a piece of paper, it should be weighed in a glassware such as a beaker.

Sodium hydroxide, with the chemical formula NaOH and commonly known as caustic soda, is a strong alkali with strong corrosiveness, generally flake or lumpy, which is easily soluble in water to form an alkaline solution and release a large amount of heat. Sodium hydroxide is easy to deliquescent in air, so solid sodium hydroxide is commonly used as a desiccant.

Sodium hydroxide will completely dissociate into sodium ions and hydroxide ions when dissolved in water, so it has the universal properties of alkali and can carry out acid-base neutralization reaction with any proton acid.

Because sodium hydroxide solids are highly corrosive and prone to deliquescent, sodium hydroxide solids should be placed in a surface dish or small beaker when weighing sodium hydroxide solids with a balance.

Sodium hydroxide is corrosive to prevent corrosion of the balance, and it cannot be in direct contact with the human body; It cannot be weighed in a humid environment because sodium hydroxide is absorbent and should be weighed in a dry environment. The time of weighing should be prevented as soon as possible from introspection with carbon dioxide in the air.

Weigh it quickly, and you can't use paper to weigh it, you have to use a glass container.

When weighing solid sodium hydroxide on a tray balance, the correct way to do this is to place the NAOH in a beaker and weigh it again. Because general drugs are weighed on paper, and drugs that are prone to deliquescent or corrosive are weighed in glassware; And to follow the principle of left object right code, because sodium hydroxide is corrosive, so it should be put in a beaker to weigh.

The glass is sodium silicate and does not react with sodium hydroxide. Sodium hydroxide solids corrode paper on paper. Weighing sodium hydroxide can be in contact with air, and deliquescent is very slow, as long as paper or other fiber products are not used.

Glass is already a very stable material and basically does not react. In the case of paper chips, it is easy to react with paper pieces in the first place, and sodium hydroxide is equivalent to direct exposure to air, and the contact area with air is relatively small when using a beaker. Therefore, it is recommended to weigh with a beaker, but it is also necessary to speed up a little, after all, it is exposed to air, and it will deliquescent after a long time!!

Sodium hydroxide will corrode the paper, in the short term, sodium hydroxide absorbs both CO2 and water is a minority, and the weighing time is only a few minutes, will not react much.

Weigh in two steps.

The first step is to weigh the quality of the glassware used.

In the second part, the total weight of sodium hydroxide and glassware can be weighed.

Glassware! Such as beakers, surface dishes, will not react in a short time!

Just weigh on the weighing paper, act quickly, because sodium hydroxide itself is easy to absorb water and deliquescent, and react with moisture and carbon dioxide in the air, so it is the same when weighed in **.

Sodium hydroxide is weighed in a beaker. Sodium hydroxide is also known as caustic soda, caustic soda, solid soda, caustic soda, and caustic soda. Sodium hydroxide has strong alkaline and strong corrosiveness, and can be used as acid neutralizer, masking agent, precipitant, precipitation masking agent, chromogenic agent, saponifying agent, peeling agent, detergent, etc., and has a wide range of uses.

There are two methods for industrial production of sodium hydroxide: causticizing and electrolysis. The causticizing method can be divided into soda ash causticization method and trona causticization method according to the different raw materials of good eggplant, and the electrolysis method can be divided into separator electrolysis method and ion exchange membrane method. The staff should take precautions, if accidentally touching the ** and eyes, should immediately wash with a large amount of water.

The working environment should have good ventilation conditions.