One Question per Day in Applied Chemistry (8-2)

Thread Content

This post was last edited by coolmaokai on 2017-8-3 09:01. Utilizing knowledge related to applied chemistry, including (analytical chemistry, physical chemistry, and principles of chemical engineering), we are launching the \"One Question per Day\" activity; replies will reveal the questions. To encourage continued participation from everyone! You get 3 wealth rewards just for participating! Correct answers earn an additional 5 wealth rewards. I hope everyone will participate actively, learn together, and make progress together! ! ! At pH=10, when titrating Ca2+ and Mg2+ in water using EDTA, what effect do Al3+, Fe3+, Ni2+, and Co2+ have on the chromogenic indicator Eriochrome Black T? How to mask? ( ) A. Sealing effect. KCN masks Al3+ and Fe3+, while triethanolamine masks Ni2+ and Co2+. B. Sealing effect. KCN masks Ni2+ and Co2+, while triethanolamine masks Al3+ and Fe3+. C. Stabilization: KCN masks Ni2+ and Co2+, and triethanolamine masks Al3+ and Fe3+. D. Stabilization: KCN masks Al3+ and Fe3+, while triethanolamine masks Ni2+ and Co2+. B