How can the content of sodium hydroxide be accurately determined in a sodium silicate-containing sodium hydroxide solution?
Thread Content
The solution under test is a mixture of sodium hydroxide, sodium silicate, sodium metasilicate, silicic acid, metasilicic acid, etc.; how can the content of sodium hydroxide be determined?
This measurement is quite complex. If the solution is alkaline, then silicic acid and metasilicic acid are not present, right? They can only exist in the form of sodium silicate and sodium metasilicate. Sodium silicate and sodium metasilicate are strong bases with weak acid salts; if the solution is highly alkaline, its alkalinity is considered to be equivalent to the amount of sodium hydroxide present. If the alkalinity is low, it is necessary to measure the amounts of sodium silicate and sodium metasilicate, and the total alkalinity is then reduced by those amounts.
So how do you measure the alkalinity of a solution? You still haven’t answered the question about the sodium hydroxide content; I want to know the specific methods!
Original poster, it’s unlikely that the concentration of sodium hydroxide can be determined separately in the mixed sample you mentioned. Because the so-called sodium silicate is also a mixture, namely composed of sodium oxide and silicon dioxide in different proportions; their molar ratio (modulus) is related to the strength of their basicity, and it can even reach neutrality – this is the composition of water glass. It is recommended that you consult laboratories in the silicate industry; they may have the testing methods and relevant professional explanations you need.