Question

what are the criteria of a secondary standard ?​

Answer 1

Answer:

High level of purity, low reactivity (high stability), high equivalent weight (to reduce error from mass measurements)  Not hygroscopic (to reduce changes in mass in humid versus dry environments), non-toxic, inexpensive and readily available  It should have a high relative molecular weight so that weighing errors ...

Answer 2

HERE IS YOUR ANSWER MATE.....;

Secondary standard in turn is used for the purpose of calibration of control material in smaller lab for analysis of unknown concentration of a substance. So basically, secondary standard serves the purpose of external quality control for smaller labs.

HOPE IT'S HELPFUL....:-)