Gwneir y lwmp #rongalite trwy ddefnyddio #sodiummetabisulfite, #zincpowder, a fformaldehyd fel deunyddiau crai i gynnal adweithiau rhydocs mewn dŵr.
The #rongalite lump is made by using #sodiummetabisulfite, #zincpowder, and formaldehyde as raw materials to carry out redox reactions in water. The reaction formula is:Na2S2O5+2Zn +2HCHO+5H2O=2NaHSO2.HCHO.2H2O +2ZnO
In the redox reaction, Na2S2O5 is the oxidant, #Zinc powder is the #reducing agent, and the reaction products are 2NaHSO2.HCHO.2H2O and ZnO.
In order to promote the completion of the reaction, not affect the purity of 2NaHSO2.HCHO.2H2O, excess Zn powder and H2O will be added , as HCHO will cause pollution and endangering the health of operators , so the HCHO is based on the theoretical amount.