Service hotline
+86-22-88303226
Customer service team:
在线客服
WhatsApp:
Service time:
8:00 - 18:00

Copyright:HAIXING ENO CHEMICAL CO.,LTD     Add:HAI XING ECONOMIC DEVELOPMENT AREA, HAI XING COUNTY 061200, HEBEI 
Tel:+86-22-88303226    Fax: +86-22-88303226    E-mail: info@enochem.com.cn   冀ICP备12012949号 


TEL:+86-13642134113 E-mail:Williamzhang@enochem.com.cn

普通文字

EXHIBITION

The effective chlorine content of sodium calcium hypochlorite was measured by iodimetry

Page view
[Abstract]:
The production of calcium hypochlorite in China adopts lime milk chloride method (calcium method) and caustic soda lime method (sodium method).

Calcium hypochlorite produced by calcium method is determined by iodine quantity method.

The purpose of this study is to determine the appropriate operating conditions for sodium calcium hypochlorite products to determine the effective chlorine content by iodimetry;

The production of calcium hypochlorite in China adopts lime milk chloride method (calcium method) and caustic soda lime method (sodium method).

Calcium hypochlorite produced by calcium method is determined by iodine quantity method.

The purpose of this study is to determine the appropriate operating conditions for sodium calcium hypochlorite products to determine the effective chlorine content by iodimetry;

At the same time, the feasibility of this method is further verified

1 Test Section

1.1 The reaction principle of effective chloridine

In acidic medium, calcium hypochlorite reacts with potassium iodide to precipitate iodine.

Starch was used as indicator and sodium thiosulfate was used as standard

Titration solution titration, the disappearance of blue is the end point.

The equation is as follows:

1.4.Experimental Section (Selection of Operating conditions)

1.4.1 Selection of potassium iodide dosage

Iodine has volatilization and is prone to volatilization loss, which brings errors to the determination results. Excessive potassium iodide solution is added in the analysis, which is 2 ~ 3 times larger than the theoretical value. I3- is generated, which can reduce the volatilization of I2.

Based on this, different amounts of potassium iodide solutions (100g/L) were added to determine the available chlorine content in sodium method calcium hypochlorite.

I. 4.2 Selection of sulfuric acid solution dosage

The reaction between S2O32- and I2 was rapid, complete, but the iodimetric titration was performed under pH 8, neutral, and slightly acidic conditions.

Under alkaline conditions, S2O32- reacts with I2 as follows.

This complicates the reaction.

Decomposition of NA2S2O3 solution in a strongly acidic solution:

In addition, I I is easily oxidized by 0 in the air in acidic solution:

This reaction proceeds very slowly in neutral solution, but accelerates with increasing H - 1 concentration in solution.

If exposed to direct sunlight.

The reaction rate is accelerated.

Therefore, iodimetry is generally carried out in neutral or weak acidic solution and at low temperature.

To reduce I I's contact with air, titrations should not be violently oscillated.

Based on the above analysis.

Different amount of sulfuric acid solution was added for comparison experiment.

I. 6 Repetitive experiments

Repeated experiments were performed on the same sample.

3 conclusion

The optimum operating conditions for the determination of effective chlorine in sodium hypochlorite by iodimetry were determined by a large number of experiments and the comparison of various operating conditions.

It is proved that the operating conditions for the determination of available chlorine by iodimetry in GB/T10666-1989 are also applicable to calcium hypochlorite products by sodium method with different processes and raw materials, thus unifying the determination methods of available chlorine for sodium method and calcium method products.

At the same time, it can be seen from the above experiments that the iodine quantity method is used to determine the effective chlorine content in sodium calcium hypochlorite products, with high accuracy, precision and good repeatability.

This method is feasible.