某些混合无机盐体系形成Liesegang环的研究

Study on the Some Mixed Inorganic Salts Forming Liesegang Ring

通过研究Cu^(2+),Hg^(2+),Pb^(2+),Zn^(2+)等数种金属离子中两种或两种以上混合离子在试管中产生的Liesegang环与单个金属离子产生的Liesegang环对比,在相当长的时间内观察发现:在一定浓度范围内,混合金属离子产生的沉淀环可彼此分离,且原子量越大的金属离子其沉淀环迁移速度越快。分析得知:在金属离子产生周期性沉淀过程中,沉淀环具有半透膜性质,离子透过规律是反应阴离子CrO_4^(2-)比反应阳离子快;阳离子则是原子量越大者透过速度越快,即Pb^(2+)>Hg^(2+)>Zn^(2+)>Cu^(2+)。

The formation of Liesegang Ring in the pptn. of the chromate of Cu^(2+), Hg^(2+), Pb^(2+) and Zn^(2+) was studied in Contrast two or three mixed metalic cations to single cation. We found that the heavier the cation is, the greater the ionic diffusion rates is. The ring acts as a semipermeable membrane when some ions reach the ring or band.Ionic diffusion rates of anion ions through the ring is greater than cation ions and cation ion with great atomic has great diffusion rates, i.e, Pb^(2+)>Hg^(2+)>Zn^(2+)>Cu^(2+).