含铁和铝的酸性溶液中盐酸的测定
AN-H-118
zh
水合离子 [Fe(H2O)6]3+ 的存在会干扰 “游离酸 ”的测定，因为该离子的 pKa 值很低（约 2.2）。金属离子（如铁、铜和铝）可被氟化物有效掩蔽，从而可以通过热计碱式滴定法准确、准确地测定酸含量。
The presence of the hydrated ion [Fe(H2O)6]3+ can interfere with the determination of «free acid» due to the low pKa (approx. 2.2) of this ion. Ions of metals such as Fe, Cu, and Al can be masked effectively with fluoride, and permit the determination of the acid content by thermometric alkalimetric titration with good accuracy and precision.