Can calcium chloride be used to identify sodium carbonate and sodium bicarbonate?

   Calcium chloride, a salt composed of chlorine and calcium, has the chemical formula CaCl2. Slightly bitter, tasteless. It is a typical ionic halide that is white, hard crumb or granules at room temperature. Common applications for food grade calcium chloride include brines, road ice melting agents and desiccants used in refrigeration equipment. Because it is easily deliquescent in the air, the anhydrous calcium chloride must be sealed and stored in the container. Calcium chloride and its hydrates and solutions have important applications in food manufacturing, building materials, medicine and biology. Calcium chloride has a prominent adsorption capacity for ammonia and a low desorption temperature, and has great application prospects in the adsorption separation of synthetic ammonia. However, since calcium chloride is not easy to form a stable porous material, the contact area with the gas ammonia is small, and it is easy to expand and agglomerate during adsorption and desorption, so that it is difficult to put it into practical use in this respect. Carrying calcium chloride on a high specific surface carrier can greatly increase the contact area between calcium chloride and gas ammonia. Related studies have shown that composite adsorbents prepared by supporting food grade calcium chloride on molecular sieves have better adsorption performance and stability than single adsorbents.

The calcium ion concentration is a low concentration of 10-5 mol·L-1, and the lowest concentration of NaHCO3 is about 0.05 mol·L-1, and CaCO3 precipitation can be produced. The concentration used in actual experiments is much larger than the calculated value. Therefore, it is not suitable to identify Na2CO3 and NaHCO3 solutions with CaCl2 solution.

    Another commonly used reagent, BaCl2, precipitates BaCO3 with Ksp = 8.1 × 10-9. The situation should be similar!

    So is it not possible to detect this?

    Calcium chloride manufacturers consulted Ksp (MgCO3) = 6.82 × 10-6, calculated according to the low magnesium ion concentration, the concentration of NaHCO3 solution needed to be about 122mol·L-1. Then, the 0.10 mol·L-1 NaHCO3 solution needs about 1.22×10-2 mol·L-1 of MgCl2 solution to precipitate, so the precipitation method must be used to distinguish Na2CO3 and NaHCO3 solution, the concentration of the two solutions should not be too high. And good choice of MgCl2 solution, its concentration can not be too high!