Industrial chloroethanol solution (3)

4.

4.

The acid in the sample is titrated with phenolphthalein as the indicator solution with sodium hydroxide standard titration solution

4.

a) Phenolphthalein indicator solution : 10g/L;

b) Sodium hydroxide standard titration solution: c(NaOH)=0.

4.

General laboratory instruments and equipment

4.

Add 30mL of water and 2~3 drops of phenolphthalein indicator solution to the Erlenmeyer flask, titrate with sodium hydroxide standard titration solution to reddish, then weigh 5.

4.

The acidity expressed by mass percentage (calculated by HCl) X _{3 is} calculated according to formula (3)

Where: V—volume of sodium hydroxide standard titration solution consumed by laboratory samples, mL;

c— The actual concentration of sodium hydroxide standard titration solution, mol/L;

m—the quality of laboratory samples, g;

0.

Take the arithmetic average of the two parallel determination results as the determination result, and the difference between the two parallel determination results shall not exceed 0.

5 Inspection rules

5.

The content of the quality certificate includes the product name, batch number, net weight, date of manufacture and the standard number

5.

Sampling method and sampler: The sampling and sampler of barreled products shall be carried out in accordance with 2.
1.
3 of GB/T6680
.
The sampling and sampler of the products in the tanker shall be carried out in accordance with the relevant regulations in 2.
3.
1 of GB/T6680
.

For large barrels, the number of sampling units should be in accordance with 6.
6 in GB/T6678
.
The sampling volume of each batch shall not be less than 500mL.
After fully mixing, divide it into two clean and dry wide-mouth bottles, seal them, affix a label and indicate the product name, batch number, sampling date, and the person who took the sample
.
One bottle is sent to the quality inspection department for inspection
.
The other bottle is kept for two months for future reference
.

5.
3 The test result is judged according to GB/T1250 rounding value comparison method
.
If there is an indicator that does not meet the requirements of this standard in the inspection results, samples should be taken from twice the amount of packaging for re-inspection.
Even if only one indicator does not meet the requirements of this standard, the entire batch of products will be unqualified
.

5.
4 The user has the right to check and accept the product quality in accordance with this standard.
When the supplier and the buyer have any objection to the product quality, they should promptly raise it and resolve it through consultation between the two parties or ask the arbitration unit for arbitration analysis
.

6 Marking, packaging, transportation and storage

6.
1 Use paint on the packaging barrel to clearly and firmly mark: the name of the manufacturer, the name of the product, the batch number of the product, the date of production, the number of this standard, and the net weight of the product
.

6.
2 This product is packed in iron drums or railway tank cars
.
When packed in iron drums, the net weight of each drum is 200kg, and the allowable weight difference is ±0.
5kg
.

6.
3 Avoid violent impacts during transportation and handling, avoid cracking of the barrel skin welds, and prevent rain and sun
.

6.
4 This product should be stored in a dry, well-ventilated warehouse or shed
.