I have a question: why is the content detected for trisodium phosphate over 100?
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Why is the result for trisodium phosphate obtained by the gravimetric method over 100? Please, experts, give me some advice
Trisodium phosphate may contain some polyphosphates; as a result, when quantifying sodium phosphate using methods for detecting phosphates, the amount of sodium phosphate reported can be higher than 100%. For example, sodium tripolyphosphate, upon complete hydrolysis, releases three phosphate ions; however, when sampling by weight, the calculation is based on sodium phosphate. The net phosphorus content of phosphate ions and tripolyphosphate ions is different, with the latter being higher than the former.
Is it possible that trisodium phosphate (12 water) contains a small amount of anhydrous trisodium phosphate? This way, the result also increases when converting
It’s probably done by colorimetry; errors increase after multiple dilutions, but this doesn’t happen if the gravimetric method is used
It is the gravimetric method, with quinomolybdate added for co-precipitation