here we introduce a simple method to test the purity of C2H2 gas on site, we dip the silver nitrate solution onto the test paper, then put the test paper under the gas sampler, if the test paper colour doesn't change, the purity of C2H2 gas can reach at least about 98%, this purity is enough to be used in industrial application.

Acetylene, molecular formula C2H2, acetylene molecular weight 26.038; molar volume under standard state 22.223L.