How to dilute corrosive reagents? Common dilution methods for acid base solutions. Be succinct in yo

Common dilution methods of acid and alkali solution include direct water soluble method, medium water soluble method, and dilution method. 1. The direct water solubilization method accurately weighs the reference substance, and the fixed volume becomes the standard solution of accurate concentration after dissolution. For example, when it is necessary to prepare 500ml of mol·l-1 K2Cr2O7 solution, the reference substance K2Cr2O7 should be accurately weighed on the analytical balance, dissolved by adding a small amount of water, quantitatively transferred to a 500ml volumetric flask, and diluted to the scale with water.

Previously, we briefly analyzed the principle and method of chemical degreasing and cleaning of aluminum alloys, and mainly mentioned the characteristics and advantages of alkaline degreasing. In fact, the application of chemical degreasing and cleaning on the surface of aluminum, acid degreasing is also a more mainstream method, we can take a look.

The degreasing and cleaning operation of aluminum alloys is also known as degreasing. Acid degreasing is mainly based on sulfuric acid, phosphoric acid and nitric acid, etc., and the hydrolysis reaction of oil and fat in acid solution is used for degreasing. Its treatment conditions are very relaxed, such as HT300 room temperature degreaser and other commonly sold degreasers in the market, can be carried out at room temperature, easy production control and low cost, at present, acid degreasing has replaced alkaline degreasing in many areas.

The main components of aluminic acid degreasing degreaser are mainly composed of organic acids, inorganic acids, solvents and a variety of emulsifiers with the ability of emulsification, cleaning, solubilization, and osmotic decomposition. Its use can be divided into soaking, spraying, wiping, and generally commonly used is soaking. Soak and dilute 25--30 times, according to the aluminum material and surface oil stain treatment time is 6-15 minutes, when the pH value becomes above, add the original solution to meet the needs of degreasing, and the treated aluminum should be oxidized and other post-treatment.

The preparation of ultrasonic-assisted cleaning has a better effect, but there is a detail that needs to be paid attention to in the degreasing process, which should not be soaked for too long, as it will corrode the metal for too long and cause the surface to be dull. Therefore, when using, it should be operated according to the product manual, or under the guidance of consulting technical personnel.

In addition to acid and alkaline degreasing reagents, some powerful R&D manufacturers have also developed neutral degreasing reagents such as HT422 neutral degreasing agent. Because aluminium acid degreaser is a very corrosive chemical agent, there is a certain danger to operate.

It is required before it can be operated.

Dilution refers to the process of diluting a solution of a certain concentration into a lower concentration solution. You may need to dilute the solution accurately or arbitrarily for a variety of reasons. For example, biochemists need to dilute the mother liquor and configure a new solution for research during an experiment, where the solution needs to be accurately diluted to a certain concentration.

Bartenders, on the other hand, often dilute spirits with soft drinks or juices to create more tasty and delicious cocktails. In general, the calculation formula we use for dilution is C1V1 = C2V2, where C1 and C2 represent the concentrations of the starting and final solutions, respectively, and V1 and V2 represent their volumes.

Add one milliliter of reagent with a concentration of C to 5 milliliters of distilled water.

Basic formula: c*v=nUse this formula to convert.

Junior Chemistry - Corrosiveness and dilution of concentrated sulfuric acid.

In the same way, the continuous dilution of alkali will not become an acid, which is equivalent to only water. ph=7

In addition to the dissolution of sulfuric acid, acid needs to be added to the water. The dilution of other acids and bases is to weigh water and medicine in proportion, and mix it.

The dissolution of zinc sulfate is in the beaker, after all the dissolution is moved into the 100ml volumetric flask, the beaker is repeatedly cleaned with distilled water, and the distilled water used for cleaning should also be moved into the volumetric flask, this process should be repeated several times, and finally the solution in the volumetric flask is fixed to the marking line with distilled water, and the stopper of the volumetric flask is reversed several times.

Put one milliliter of the reagent at a concentration of C and add distilled water.

Up to 5 ml is sufficient.

Basic formula: c*v=nUse this formula to convert.

For example, how do I dilute a solution 1000-fold?

First, measure the volume of the solution to be measured. And multiply it by 1000 times to calculate the result. Then pour it into a suitable beaker, pour in an appropriate amount of water, mix evenly, pour it into a suitable volumetric flask, then add water to it, shake it gently as you add until it is 2-3 mm from the scale mark, then use a dropper to drop it and fill it up.

Beaker, glass rod, graduated cylinder.

Because the concentrated solution and water are liquids, it is inconvenient to weigh the quality and distribute the quantity, so instead of using a balance, a measuring cylinder is used, and then the mass is calculated according to the density. Travel.

Calculations regarding the dilution of the solution.

Problem solving tips: On the basis of mastering the fact that the quality of the solute remains unchanged before and after dilution of the solution, understand and apply the following relations:

m (concentrated) xa% = m (dilute) xb%, where m (concentrated) and a% represent the mass of concentrated solution and its solute mass fraction, respectively;

m (diluted) and b% represent the amount of dilute solution, respectively.

Precautions for problem solving: Be sure to find the corresponding amount of concentration and dilution.

Example. How much water should be added to dilute 50g of concentrated sulfuric acid with a solute mass fraction of 98% into 20% dilute sulfuric acid?

Analysis: If the mass of water to be added is x, then the mass of the diluted solution is, then 50g 98% (50g x) 20%. Solution x 195g.